diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__model.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__model.mustache
index 764211e2120..98b56e3d154 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__model.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__model.mustache
@@ -1,6 +1,7 @@
 # coding: utf-8
 
+# flake8: noqa
 from __future__ import absolute_import
 # import models into model package
-{{#models}}{{#model}}from .{{classFilename}} import {{classname}}{{/model}}
+{{#models}}{{#model}}from {{modelPackage}}.{{classFilename}} import {{classname}}{{/model}}
 {{/models}}
\ No newline at end of file
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__test.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__test.mustache
index 77b10c3a012..9cea80bc630 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__test.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/__init__test.mustache
@@ -1,8 +1,10 @@
-from flask_testing import TestCase
-from ..encoder import JSONEncoder
-import connexion
 import logging
 
+import connexion
+from flask_testing import TestCase
+
+from {{packageName}}.encoder import JSONEncoder
+
 
 class BaseTestCase(TestCase):
 
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/__main__.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/__main__.mustache
index 8884887471f..10756347223 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/__main__.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/__main__.mustache
@@ -6,13 +6,14 @@
 {{/supportPython2}}
 
 import connexion
-from .encoder import JSONEncoder
+
+from {{packageName}} import encoder
 
 
 def main():
     app = connexion.App(__name__, specification_dir='./swagger/')
-    app.app.json_encoder = JSONEncoder
-    app.add_api('swagger.yaml', arguments={'title': '{{appDescription}}'})
+    app.app.json_encoder = encoder.JSONEncoder
+    app.add_api('swagger.yaml', arguments={'title': '{{appName}}'})
     app.run(port={{serverPort}})
 
 
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/base_model_.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/base_model_.mustache
index 6e3464c7019..54517a06d53 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/base_model_.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/base_model_.mustache
@@ -1,38 +1,39 @@
-from pprint import pformat
+import pprint
+
+import six
 {{^supportPython2}}
-from typing import TypeVar, Type
+import typing
 {{/supportPython2}}
-from six import iteritems
-from ..util import deserialize_model
+
+from {{packageName}} import util
 {{^supportPython2}}
 
-T = TypeVar('T')
+T = typing.TypeVar('T')
 {{/supportPython2}}
 
 
 class Model(object):
-    # swaggerTypes: The key is attribute name and the value is attribute type.
+    # swaggerTypes: The key is attribute name and the
+    # value is attribute type.
     swagger_types = {}
 
-    # attributeMap: The key is attribute name and the value is json key in definition.
+    # attributeMap: The key is attribute name and the
+    # value is json key in definition.
     attribute_map = {}
 
     @classmethod
-    def from_dict(cls{{^supportPython2}}: Type[T]{{/supportPython2}}, dikt){{^supportPython2}} -> T{{/supportPython2}}:
-        """
-        Returns the dict as a model
-        """
-        return deserialize_model(dikt, cls)
+    def from_dict(cls{{^supportPython2}}: typing.Type[T]{{/supportPython2}}, dikt){{^supportPython2}} -> T{{/supportPython2}}:
+        """Returns the dict as a model"""
+        return util.deserialize_model(dikt, cls)
 
     def to_dict(self):
-        """
-        Returns the model properties as a dict
+        """Returns the model properties as a dict
 
         :rtype: dict
         """
         result = {}
 
-        for attr, _ in iteritems(self.swagger_types):
+        for attr, _ in six.iteritems(self.swagger_types):
             value = getattr(self, attr)
             if isinstance(value, list):
                 result[attr] = list(map(
@@ -53,27 +54,20 @@ class Model(object):
         return result
 
     def to_str(self):
-        """
-        Returns the string representation of the model
+        """Returns the string representation of the model
 
         :rtype: str
         """
-        return pformat(self.to_dict())
+        return pprint.pformat(self.to_dict())
 
     def __repr__(self):
-        """
-        For `print` and `pprint`
-        """
+        """For `print` and `pprint`"""
         return self.to_str()
 
     def __eq__(self, other):
-        """
-        Returns true if both objects are equal
-        """
+        """Returns true if both objects are equal"""
         return self.__dict__ == other.__dict__
 
     def __ne__(self, other):
-        """
-        Returns true if both objects are not equal
-        """
-        return not self == other
\ No newline at end of file
+        """Returns true if both objects are not equal"""
+        return not self == other
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/controller.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/controller.mustache
index 8fc01dbd7ac..b865222c7d2 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/controller.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/controller.mustache
@@ -1,18 +1,18 @@
 import connexion
-{{#imports}}{{import}}
+import six
+
+{{#imports}}{{import}}  # noqa: E501
 {{/imports}}
-from datetime import date, datetime
-from typing import List, Dict
-from six import iteritems
-from ..util import deserialize_date, deserialize_datetime
+from {{packageName}} import util
 {{#operations}}
 {{#operation}}
 
 
-def {{operationId}}({{#allParams}}{{paramName}}{{^required}}=None{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}}):
-    """
-    {{#summary}}{{.}}{{/summary}}{{^summary}}{{operationId}}{{/summary}}
-    {{#notes}}{{.}}{{/notes}}
+def {{operationId}}({{#allParams}}{{paramName}}{{^required}}=None{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}}):  # noqa: E501
+    """{{#summary}}{{.}}{{/summary}}{{^summary}}{{operationId}}{{/summary}}
+
+    {{#notes}}{{.}}{{/notes}} # noqa: E501
+
     {{#allParams}}
     :param {{paramName}}: {{description}}
         {{^isContainer}}
@@ -55,15 +55,15 @@ def {{operationId}}({{#allParams}}{{paramName}}{{^required}}=None{{/required}}{{
     {{#allParams}}
         {{^isContainer}}
             {{#isDate}}
-    {{paramName}} = deserialize_date({{paramName}})
+    {{paramName}} = util.deserialize_date({{paramName}})
             {{/isDate}}
             {{#isDateTime}}
-    {{paramName}} = deserialize_datetime({{paramName}})
+    {{paramName}} = util.deserialize_datetime({{paramName}})
             {{/isDateTime}}
             {{^isPrimitiveType}}
                 {{^isFile}}
     if connexion.request.is_json:
-        {{paramName}} = {{baseType}}.from_dict(connexion.request.get_json())
+        {{paramName}} = {{baseType}}.from_dict(connexion.request.get_json())  # noqa: E501
                 {{/isFile}}
             {{/isPrimitiveType}}
         {{/isContainer}}
@@ -71,15 +71,15 @@ def {{operationId}}({{#allParams}}{{paramName}}{{^required}}=None{{/required}}{{
             {{#items}}
                 {{#isDate}}
     if connexion.request.is_json:
-        {{paramName}} = [deserialize_date(s) for s in connexion.request.get_json()]
+        {{paramName}} = [util.deserialize_date(s) for s in connexion.request.get_json()]  # noqa: E501
                 {{/isDate}}
                 {{#isDateTime}}
     if connexion.request.is_json:
-        {{paramName}} = [deserialize_datetime(s) for s in connexion.request.get_json()]
+        {{paramName}} = [util.deserialize_datetime(s) for s in connexion.request.get_json()]  # noqa: E501
                 {{/isDateTime}}
                 {{#complexType}}
     if connexion.request.is_json:
-        {{paramName}} = [{{complexType}}.from_dict(d) for d in connexion.request.get_json()]
+        {{paramName}} = [{{complexType}}.from_dict(d) for d in connexion.request.get_json()]  # noqa: E501
                 {{/complexType}}
             {{/items}}
         {{/isListContainer}}
@@ -87,15 +87,15 @@ def {{operationId}}({{#allParams}}{{paramName}}{{^required}}=None{{/required}}{{
             {{#items}}
                 {{#isDate}}
     if connexion.request.is_json:
-        {{paramName}} = {k: deserialize_date(v) for k, v in iteritems(connexion.request.get_json())}
+        {{paramName}} = {k: util.deserialize_date(v) for k, v in six.iteritems(connexion.request.get_json())}  # noqa: E501
                 {{/isDate}}
                 {{#isDateTime}}
     if connexion.request.is_json:
-        {{paramName}} = {k: deserialize_datetime(v) for k, v in iteritems(connexion.request.get_json())}
+        {{paramName}} = {k: util.deserialize_datetime(v) for k, v in six.iteritems(connexion.request.get_json())}  # noqa: E501
                 {{/isDateTime}}
                 {{#complexType}}
     if connexion.request.is_json:
-        {{paramName}} = {k: {{baseType}}.from_dict(v) for k, v in iteritems(connexion.request.get_json())}
+        {{paramName}} = {k: {{baseType}}.from_dict(v) for k, v in six.iteritems(connexion.request.get_json())}  # noqa: E501
                 {{/complexType}}
             {{/items}}
         {{/isMapContainer}}
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/controller_test.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/controller_test.mustache
index 7b202bb9126..a41b12f2c21 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/controller_test.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/controller_test.mustache
@@ -2,20 +2,20 @@
 
 from __future__ import absolute_import
 
-{{#imports}}{{import}}
-{{/imports}}
-from . import BaseTestCase
-from six import BytesIO
 from flask import json
+from six import BytesIO
+
+{{#imports}}{{import}}  # noqa: E501
+{{/imports}}
+from {{packageName}}.test import BaseTestCase
 
 
 class {{#operations}}Test{{classname}}(BaseTestCase):
-    """ {{classname}} integration test stubs """
+    """{{classname}} integration test stubs"""
 
    {{#operation}}
     def test_{{operationId}}(self):
-        """
-        Test case for {{{operationId}}}
+        """Test case for {{{operationId}}}
 
         {{{summary}}}
         """
@@ -31,15 +31,17 @@ class {{#operations}}Test{{classname}}(BaseTestCase):
         {{#formParams}}
         {{#-first}}data = dict({{/-first}}{{^-first}}            {{/-first}}{{paramName}}={{{example}}}{{#hasMore}},{{/hasMore}}{{#-last}}){{/-last}}
         {{/formParams}}
-        response = self.client.open('{{#contextPath}}{{{.}}}{{/contextPath}}{{{path}}}'{{#pathParams}}{{#-first}}.format({{/-first}}{{paramName}}={{{example}}}{{#hasMore}}, {{/hasMore}}{{^hasMore}}){{/hasMore}}{{/pathParams}},
-                                    method='{{httpMethod}}'{{#bodyParam}},
-                                    data=json.dumps({{paramName}}){{^consumes}},
-                                    content_type='application/json'{{/consumes}}{{/bodyParam}}{{#headerParams}}{{#-first}},
-                                    headers=headers{{/-first}}{{/headerParams}}{{#formParams}}{{#-first}},
-                                    data=data{{/-first}}{{/formParams}}{{#consumes}}{{#-first}},
-                                    content_type='{{{mediaType}}}'{{/-first}}{{/consumes}}{{#queryParams}}{{#-first}},
-                                    query_string=query_string{{/-first}}{{/queryParams}})
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '{{#contextPath}}{{{.}}}{{/contextPath}}{{{path}}}'{{#pathParams}}{{#-first}}.format({{/-first}}{{paramName}}={{{example}}}{{#hasMore}}, {{/hasMore}}{{^hasMore}}){{/hasMore}}{{/pathParams}},
+            method='{{httpMethod}}'{{#bodyParam}},
+            data=json.dumps({{paramName}}){{^consumes}},
+            content_type='application/json'{{/consumes}}{{/bodyParam}}{{#headerParams}}{{#-first}},
+            headers=headers{{/-first}}{{/headerParams}}{{#formParams}}{{#-first}},
+            data=data{{/-first}}{{/formParams}}{{#consumes}}{{#-first}},
+            content_type='{{{mediaType}}}'{{/-first}}{{/consumes}}{{#queryParams}}{{#-first}},
+            query_string=query_string{{/-first}}{{/queryParams}})
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
    {{/operation}}
 {{/operations}}
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/encoder.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/encoder.mustache
index 996d74f21e7..e303a0e41a7 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/encoder.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/encoder.mustache
@@ -1,6 +1,8 @@
-from six import iteritems
-from {{modelPackage}}.base_model_ import Model
 from connexion.apps.flask_app import FlaskJSONEncoder
+import six
+
+from {{modelPackage}}.base_model_ import Model
+
 
 class JSONEncoder(FlaskJSONEncoder):
     include_nulls = False
@@ -8,11 +10,11 @@ class JSONEncoder(FlaskJSONEncoder):
     def default(self, o):
         if isinstance(o, Model):
             dikt = {}
-            for attr, _ in iteritems(o.swagger_types):
+            for attr, _ in six.iteritems(o.swagger_types):
                 value = getattr(o, attr)
                 if value is None and not self.include_nulls:
                     continue
                 attr = o.attribute_map[attr]
                 dikt[attr] = value
             return dikt
-        return FlaskJSONEncoder.default(self, o)
\ No newline at end of file
+        return FlaskJSONEncoder.default(self, o)
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/model.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/model.mustache
index 761492870bf..44bb954db2f 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/model.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/model.mustache
@@ -1,73 +1,74 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-{{#imports}}{{import}}
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from {{modelPackage}}.base_model_ import Model
+{{#imports}}{{import}}  # noqa: E501
 {{/imports}}
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from {{packageName}} import util
 
 
 {{#models}}
 {{#model}}
 class {{classname}}(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
-    Do not edit the class manually.
-    """
+    """NOTE: This class is auto generated by the swagger code generator program.
+
+    Do not edit the class manually.
+    """{{#allowableValues}}
 
-{{#allowableValues}}
     """
     allowed enum values
     """
 {{#enumVars}}
-    {{name}} = {{{value}}}
-{{/enumVars}}
-{{/allowableValues}}
+    {{name}} = {{{value}}}{{^-last}}
+{{/-last}}
+{{/enumVars}}{{/allowableValues}}
 
-    def __init__(self{{#vars}}, {{name}}{{^supportPython2}}: {{datatype}}{{/supportPython2}}={{#defaultValue}}{{{defaultValue}}}{{/defaultValue}}{{^defaultValue}}None{{/defaultValue}}{{/vars}}):
-        """
-        {{classname}} - a model defined in Swagger
+    def __init__(self{{#vars}}, {{name}}{{^supportPython2}}: {{datatype}}{{/supportPython2}}={{#defaultValue}}{{{defaultValue}}}{{/defaultValue}}{{^defaultValue}}None{{/defaultValue}}{{/vars}}):  # noqa: E501
+        """{{classname}} - a model defined in Swagger
 
         {{#vars}}
-        :param {{name}}: The {{name}} of this {{classname}}.
+        :param {{name}}: The {{name}} of this {{classname}}.  # noqa: E501
         :type {{name}}: {{datatype}}
         {{/vars}}
         """
         self.swagger_types = {
-            {{#vars}}'{{name}}': {{{datatype}}}{{#hasMore}},
-            {{/hasMore}}{{/vars}}
+{{#vars}}
+            '{{name}}': {{{datatype}}}{{#hasMore}},{{/hasMore}}
+{{/vars}}
         }
 
         self.attribute_map = {
-            {{#vars}}'{{name}}': '{{baseName}}'{{#hasMore}},
-            {{/hasMore}}{{/vars}}
-        }
-
 {{#vars}}
+            '{{name}}': '{{baseName}}'{{#hasMore}},{{/hasMore}}
+{{/vars}}
+        }
+{{#vars}}{{#-first}}
+{{/-first}}
         self._{{name}} = {{name}}
 {{/vars}}
 
     @classmethod
     def from_dict(cls, dikt){{^supportPython2}} -> '{{classname}}'{{/supportPython2}}:
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The {{name}} of this {{classname}}.
+        :return: The {{name}} of this {{classname}}.  # noqa: E501
         :rtype: {{classname}}
         """
-        return deserialize_model(dikt, cls)
-{{#vars}}{{#-first}}
+        return util.deserialize_model(dikt, cls){{#vars}}{{#-first}}
+
 {{/-first}}
     @property
     def {{name}}(self){{^supportPython2}} -> {{datatype}}{{/supportPython2}}:
-        """
-        Gets the {{name}} of this {{classname}}.
+        """Gets the {{name}} of this {{classname}}.
+
         {{#description}}
-        {{{description}}}
+        {{{description}}}  # noqa: E501
         {{/description}}
 
         :return: The {{name}} of this {{classname}}.
@@ -77,31 +78,31 @@ class {{classname}}(Model):
 
     @{{name}}.setter
     def {{name}}(self, {{name}}{{^supportPython2}}: {{datatype}}{{/supportPython2}}):
-        """
-        Sets the {{name}} of this {{classname}}.
+        """Sets the {{name}} of this {{classname}}.
+
         {{#description}}
-        {{{description}}}
+        {{{description}}}  # noqa: E501
         {{/description}}
 
         :param {{name}}: The {{name}} of this {{classname}}.
         :type {{name}}: {{datatype}}
         """
 {{#isEnum}}
-        allowed_values = [{{#allowableValues}}{{#values}}"{{{this}}}"{{^-last}}, {{/-last}}{{/values}}{{/allowableValues}}]
+        allowed_values = [{{#allowableValues}}{{#values}}"{{{this}}}"{{^-last}}, {{/-last}}{{/values}}{{/allowableValues}}]  # noqa: E501
 {{#isContainer}}
 {{#isListContainer}}
         if not set({{{name}}}).issubset(set(allowed_values)):
             raise ValueError(
-                "Invalid values for `{{{name}}}` [{0}], must be a subset of [{1}]"
-                .format(", ".join(map(str, set({{{name}}})-set(allowed_values))),
+                "Invalid values for `{{{name}}}` [{0}], must be a subset of [{1}]"  # noqa: E501
+                .format(", ".join(map(str, set({{{name}}})-set(allowed_values))),  # noqa: E501
                         ", ".join(map(str, allowed_values)))
             )
 {{/isListContainer}}
 {{#isMapContainer}}
         if not set({{{name}}}.keys()).issubset(set(allowed_values)):
             raise ValueError(
-                "Invalid keys in `{{{name}}}` [{0}], must be a subset of [{1}]"
-                .format(", ".join(map(str, set({{{name}}}.keys())-set(allowed_values))),
+                "Invalid keys in `{{{name}}}` [{0}], must be a subset of [{1}]"  # noqa: E501
+                .format(", ".join(map(str, set({{{name}}}.keys())-set(allowed_values))),  # noqa: E501
                         ", ".join(map(str, allowed_values)))
             )
 {{/isMapContainer}}
@@ -117,42 +118,44 @@ class {{classname}}(Model):
 {{^isEnum}}
 {{#required}}
         if {{name}} is None:
-            raise ValueError("Invalid value for `{{name}}`, must not be `None`")
+            raise ValueError("Invalid value for `{{name}}`, must not be `None`")  # noqa: E501
 {{/required}}
 {{#hasValidation}}
 {{#maxLength}}
         if {{name}} is not None and len({{name}}) > {{maxLength}}:
-            raise ValueError("Invalid value for `{{name}}`, length must be less than or equal to `{{maxLength}}`")
+            raise ValueError("Invalid value for `{{name}}`, length must be less than or equal to `{{maxLength}}`")  # noqa: E501
 {{/maxLength}}
 {{#minLength}}
         if {{name}} is not None and len({{name}}) < {{minLength}}:
-            raise ValueError("Invalid value for `{{name}}`, length must be greater than or equal to `{{minLength}}`")
+            raise ValueError("Invalid value for `{{name}}`, length must be greater than or equal to `{{minLength}}`")  # noqa: E501
 {{/minLength}}
 {{#maximum}}
-        if {{name}} is not None and {{name}} >{{#exclusiveMaximum}}={{/exclusiveMaximum}} {{maximum}}:
-            raise ValueError("Invalid value for `{{name}}`, must be a value less than {{^exclusiveMaximum}}or equal to {{/exclusiveMaximum}}`{{maximum}}`")
+        if {{name}} is not None and {{name}} >{{#exclusiveMaximum}}={{/exclusiveMaximum}} {{maximum}}:  # noqa: E501
+            raise ValueError("Invalid value for `{{name}}`, must be a value less than {{^exclusiveMaximum}}or equal to {{/exclusiveMaximum}}`{{maximum}}`")  # noqa: E501
 {{/maximum}}
 {{#minimum}}
-        if {{name}} is not None and {{name}} <{{#exclusiveMinimum}}={{/exclusiveMinimum}} {{minimum}}:
-            raise ValueError("Invalid value for `{{name}}`, must be a value greater than {{^exclusiveMinimum}}or equal to {{/exclusiveMinimum}}`{{minimum}}`")
+        if {{name}} is not None and {{name}} <{{#exclusiveMinimum}}={{/exclusiveMinimum}} {{minimum}}:  # noqa: E501
+            raise ValueError("Invalid value for `{{name}}`, must be a value greater than {{^exclusiveMinimum}}or equal to {{/exclusiveMinimum}}`{{minimum}}`")  # noqa: E501
 {{/minimum}}
 {{#pattern}}
-        if {{name}} is not None and not re.search('{{{vendorExtensions.x-regex}}}', {{name}}{{#vendorExtensions.x-modifiers}}{{#-first}}, flags={{/-first}}re.{{.}}{{^-last}} | {{/-last}}{{/vendorExtensions.x-modifiers}}):
-            raise ValueError("Invalid value for `{{name}}`, must be a follow pattern or equal to `{{{pattern}}}`")
+        if {{name}} is not None and not re.search('{{{vendorExtensions.x-regex}}}', {{name}}{{#vendorExtensions.x-modifiers}}{{#-first}}, flags={{/-first}}re.{{.}}{{^-last}} | {{/-last}}{{/vendorExtensions.x-modifiers}}):  # noqa: E501
+            raise ValueError("Invalid value for `{{name}}`, must be a follow pattern or equal to `{{{pattern}}}`")  # noqa: E501
 {{/pattern}}
 {{#maxItems}}
         if {{name}} is not None and len({{name}}) > {{maxItems}}:
-            raise ValueError("Invalid value for `{{name}}`, number of items must be less than or equal to `{{maxItems}}`")
+            raise ValueError("Invalid value for `{{name}}`, number of items must be less than or equal to `{{maxItems}}`")  # noqa: E501
 {{/maxItems}}
 {{#minItems}}
         if {{name}} is not None and len({{name}}) < {{minItems}}:
-            raise ValueError("Invalid value for `{{name}}`, number of items must be greater than or equal to `{{minItems}}`")
+            raise ValueError("Invalid value for `{{name}}`, number of items must be greater than or equal to `{{minItems}}`")  # noqa: E501
 {{/minItems}}
 {{/hasValidation}}
 {{/isEnum}}
 
-        self._{{name}} = {{name}}
+        self._{{name}} = {{name}}{{^-last}}
 
+{{/-last}}
 {{/vars}}
+
 {{/model}}
-{{/models}}
+{{/models}}
\ No newline at end of file
diff --git a/modules/swagger-codegen/src/main/resources/flaskConnexion/util.mustache b/modules/swagger-codegen/src/main/resources/flaskConnexion/util.mustache
index 40c72d43ebd..b0576ef9594 100644
--- a/modules/swagger-codegen/src/main/resources/flaskConnexion/util.mustache
+++ b/modules/swagger-codegen/src/main/resources/flaskConnexion/util.mustache
@@ -1,11 +1,11 @@
-from typing import GenericMeta
-from datetime import datetime, date
-from six import integer_types, iteritems
+import datetime
+
+import six
+import typing
 
 
 def _deserialize(data, klass):
-    """
-    Deserializes dict, list, str into an object.
+    """Deserializes dict, list, str into an object.
 
     :param data: dict, list or str.
     :param klass: class literal, or string of class name.
@@ -15,15 +15,15 @@ def _deserialize(data, klass):
     if data is None:
         return None
 
-    if klass in integer_types or klass in (float, str, bool):
+    if klass in six.integer_types or klass in (float, str, bool):
         return _deserialize_primitive(data, klass)
     elif klass == object:
         return _deserialize_object(data)
-    elif klass == date:
+    elif klass == datetime.date:
         return deserialize_date(data)
-    elif klass == datetime:
+    elif klass == datetime.datetime:
         return deserialize_datetime(data)
-    elif type(klass) == GenericMeta:
+    elif type(klass) == typing.GenericMeta:
         if klass.__extra__ == list:
             return _deserialize_list(data, klass.__args__[0])
         if klass.__extra__ == dict:
@@ -33,8 +33,7 @@ def _deserialize(data, klass):
 
 
 def _deserialize_primitive(data, klass):
-    """
-    Deserializes to primitive type.
+    """Deserializes to primitive type.
 
     :param data: data to deserialize.
     :param klass: class literal.
@@ -52,8 +51,7 @@ def _deserialize_primitive(data, klass):
 
 
 def _deserialize_object(value):
-    """
-    Return a original value.
+    """Return a original value.
 
     :return: object.
     """
@@ -61,8 +59,7 @@ def _deserialize_object(value):
 
 
 def deserialize_date(string):
-    """
-    Deserializes string to date.
+    """Deserializes string to date.
 
     :param string: str.
     :type string: str
@@ -77,8 +74,7 @@ def deserialize_date(string):
 
 
 def deserialize_datetime(string):
-    """
-    Deserializes string to datetime.
+    """Deserializes string to datetime.
 
     The string should be in iso8601 datetime format.
 
@@ -95,8 +91,7 @@ def deserialize_datetime(string):
 
 
 def deserialize_model(data, klass):
-    """
-    Deserializes list or dict to model.
+    """Deserializes list or dict to model.
 
     :param data: dict, list.
     :type data: dict | list
@@ -108,7 +103,7 @@ def deserialize_model(data, klass):
     if not instance.swagger_types:
         return data
 
-    for attr, attr_type in iteritems(instance.swagger_types):
+    for attr, attr_type in six.iteritems(instance.swagger_types):
         if data is not None \
                 and instance.attribute_map[attr] in data \
                 and isinstance(data, (list, dict)):
@@ -119,8 +114,7 @@ def deserialize_model(data, klass):
 
 
 def _deserialize_list(data, boxed_type):
-    """
-    Deserializes a list and its elements.
+    """Deserializes a list and its elements.
 
     :param data: list to deserialize.
     :type data: list
@@ -133,10 +127,8 @@ def _deserialize_list(data, boxed_type):
             for sub_data in data]
 
 
-
 def _deserialize_dict(data, boxed_type):
-    """
-    Deserializes a dict and its elements.
+    """Deserializes a dict and its elements.
 
     :param data: dict to deserialize.
     :type data: dict
@@ -146,4 +138,4 @@ def _deserialize_dict(data, boxed_type):
     :rtype: dict
     """
     return {k: _deserialize(v, boxed_type)
-            for k, v in iteritems(data)}
+            for k, v in six.iteritems(data)}
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/__main__.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/__main__.py
index 3310c69bea7..9f4473760ee 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/__main__.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/__main__.py
@@ -1,13 +1,14 @@
 #!/usr/bin/env python
 
 import connexion
-from .encoder import JSONEncoder
+
+from swagger_server import encoder
 
 
 def main():
     app = connexion.App(__name__, specification_dir='./swagger/')
-    app.app.json_encoder = JSONEncoder
-    app.add_api('swagger.yaml', arguments={'title': 'This is a sample server Petstore server.  You can find out more about Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net, #swagger](http://swagger.io/irc/).  For this sample, you can use the api key &#x60;special-key&#x60; to test the authorization filters.'})
+    app.app.json_encoder = encoder.JSONEncoder
+    app.add_api('swagger.yaml', arguments={'title': 'Swagger Petstore'})
     app.run(port=8080)
 
 
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/pet_controller.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/pet_controller.py
index 5a999aae88f..5de865c908a 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/pet_controller.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/pet_controller.py
@@ -1,30 +1,31 @@
 import connexion
-from swagger_server.models.api_response import ApiResponse
-from swagger_server.models.pet import Pet
-from datetime import date, datetime
-from typing import List, Dict
-from six import iteritems
-from ..util import deserialize_date, deserialize_datetime
+import six
+
+from swagger_server.models.api_response import ApiResponse  # noqa: E501
+from swagger_server.models.pet import Pet  # noqa: E501
+from swagger_server import util
 
 
-def add_pet(body):
-    """
-    Add a new pet to the store
-    
+def add_pet(body):  # noqa: E501
+    """Add a new pet to the store
+
+     # noqa: E501
+
     :param body: Pet object that needs to be added to the store
     :type body: dict | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = Pet.from_dict(connexion.request.get_json())
+        body = Pet.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
 
 
-def delete_pet(petId, api_key=None):
-    """
-    Deletes a pet
-    
+def delete_pet(petId, api_key=None):  # noqa: E501
+    """Deletes a pet
+
+     # noqa: E501
+
     :param petId: Pet id to delete
     :type petId: int
     :param api_key: 
@@ -35,10 +36,11 @@ def delete_pet(petId, api_key=None):
     return 'do some magic!'
 
 
-def find_pets_by_status(status):
-    """
-    Finds Pets by status
-    Multiple status values can be provided with comma separated strings
+def find_pets_by_status(status):  # noqa: E501
+    """Finds Pets by status
+
+    Multiple status values can be provided with comma separated strings # noqa: E501
+
     :param status: Status values that need to be considered for filter
     :type status: List[str]
 
@@ -47,10 +49,11 @@ def find_pets_by_status(status):
     return 'do some magic!'
 
 
-def find_pets_by_tags(tags):
-    """
-    Finds Pets by tags
-    Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+def find_pets_by_tags(tags):  # noqa: E501
+    """Finds Pets by tags
+
+    Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing. # noqa: E501
+
     :param tags: Tags to filter by
     :type tags: List[str]
 
@@ -59,10 +62,11 @@ def find_pets_by_tags(tags):
     return 'do some magic!'
 
 
-def get_pet_by_id(petId):
-    """
-    Find pet by ID
-    Returns a single pet
+def get_pet_by_id(petId):  # noqa: E501
+    """Find pet by ID
+
+    Returns a single pet # noqa: E501
+
     :param petId: ID of pet to return
     :type petId: int
 
@@ -71,24 +75,26 @@ def get_pet_by_id(petId):
     return 'do some magic!'
 
 
-def update_pet(body):
-    """
-    Update an existing pet
-    
+def update_pet(body):  # noqa: E501
+    """Update an existing pet
+
+     # noqa: E501
+
     :param body: Pet object that needs to be added to the store
     :type body: dict | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = Pet.from_dict(connexion.request.get_json())
+        body = Pet.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
 
 
-def update_pet_with_form(petId, name=None, status=None):
-    """
-    Updates a pet in the store with form data
-    
+def update_pet_with_form(petId, name=None, status=None):  # noqa: E501
+    """Updates a pet in the store with form data
+
+     # noqa: E501
+
     :param petId: ID of pet that needs to be updated
     :type petId: int
     :param name: Updated name of the pet
@@ -101,10 +107,11 @@ def update_pet_with_form(petId, name=None, status=None):
     return 'do some magic!'
 
 
-def upload_file(petId, additionalMetadata=None, file=None):
-    """
-    uploads an image
-    
+def upload_file(petId, additionalMetadata=None, file=None):  # noqa: E501
+    """uploads an image
+
+     # noqa: E501
+
     :param petId: ID of pet to update
     :type petId: int
     :param additionalMetadata: Additional data to pass to server
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/store_controller.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/store_controller.py
index 0cdcaf445dc..eae3546c21e 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/store_controller.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/store_controller.py
@@ -1,15 +1,15 @@
 import connexion
-from swagger_server.models.order import Order
-from datetime import date, datetime
-from typing import List, Dict
-from six import iteritems
-from ..util import deserialize_date, deserialize_datetime
+import six
+
+from swagger_server.models.order import Order  # noqa: E501
+from swagger_server import util
 
 
-def delete_order(orderId):
-    """
-    Delete purchase order by ID
-    For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
+def delete_order(orderId):  # noqa: E501
+    """Delete purchase order by ID
+
+    For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors # noqa: E501
+
     :param orderId: ID of the order that needs to be deleted
     :type orderId: str
 
@@ -18,20 +18,22 @@ def delete_order(orderId):
     return 'do some magic!'
 
 
-def get_inventory():
-    """
-    Returns pet inventories by status
-    Returns a map of status codes to quantities
+def get_inventory():  # noqa: E501
+    """Returns pet inventories by status
+
+    Returns a map of status codes to quantities # noqa: E501
+
 
     :rtype: Dict[str, int]
     """
     return 'do some magic!'
 
 
-def get_order_by_id(orderId):
-    """
-    Find purchase order by ID
-    For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
+def get_order_by_id(orderId):  # noqa: E501
+    """Find purchase order by ID
+
+    For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions # noqa: E501
+
     :param orderId: ID of pet that needs to be fetched
     :type orderId: int
 
@@ -40,15 +42,16 @@ def get_order_by_id(orderId):
     return 'do some magic!'
 
 
-def place_order(body):
-    """
-    Place an order for a pet
-    
+def place_order(body):  # noqa: E501
+    """Place an order for a pet
+
+     # noqa: E501
+
     :param body: order placed for purchasing the pet
     :type body: dict | bytes
 
     :rtype: Order
     """
     if connexion.request.is_json:
-        body = Order.from_dict(connexion.request.get_json())
+        body = Order.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/user_controller.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/user_controller.py
index 9a88626c5b8..c7c3ee3519a 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/user_controller.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/controllers/user_controller.py
@@ -1,57 +1,60 @@
 import connexion
-from swagger_server.models.user import User
-from datetime import date, datetime
-from typing import List, Dict
-from six import iteritems
-from ..util import deserialize_date, deserialize_datetime
+import six
+
+from swagger_server.models.user import User  # noqa: E501
+from swagger_server import util
 
 
-def create_user(body):
-    """
-    Create user
-    This can only be done by the logged in user.
+def create_user(body):  # noqa: E501
+    """Create user
+
+    This can only be done by the logged in user. # noqa: E501
+
     :param body: Created user object
     :type body: dict | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = User.from_dict(connexion.request.get_json())
+        body = User.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
 
 
-def create_users_with_array_input(body):
-    """
-    Creates list of users with given input array
-    
+def create_users_with_array_input(body):  # noqa: E501
+    """Creates list of users with given input array
+
+     # noqa: E501
+
     :param body: List of user object
     :type body: list | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = [User.from_dict(d) for d in connexion.request.get_json()]
+        body = [User.from_dict(d) for d in connexion.request.get_json()]  # noqa: E501
     return 'do some magic!'
 
 
-def create_users_with_list_input(body):
-    """
-    Creates list of users with given input array
-    
+def create_users_with_list_input(body):  # noqa: E501
+    """Creates list of users with given input array
+
+     # noqa: E501
+
     :param body: List of user object
     :type body: list | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = [User.from_dict(d) for d in connexion.request.get_json()]
+        body = [User.from_dict(d) for d in connexion.request.get_json()]  # noqa: E501
     return 'do some magic!'
 
 
-def delete_user(username):
-    """
-    Delete user
-    This can only be done by the logged in user.
+def delete_user(username):  # noqa: E501
+    """Delete user
+
+    This can only be done by the logged in user. # noqa: E501
+
     :param username: The name that needs to be deleted
     :type username: str
 
@@ -60,10 +63,11 @@ def delete_user(username):
     return 'do some magic!'
 
 
-def get_user_by_name(username):
-    """
-    Get user by user name
-    
+def get_user_by_name(username):  # noqa: E501
+    """Get user by user name
+
+     # noqa: E501
+
     :param username: The name that needs to be fetched. Use user1 for testing. 
     :type username: str
 
@@ -72,10 +76,11 @@ def get_user_by_name(username):
     return 'do some magic!'
 
 
-def login_user(username, password):
-    """
-    Logs user into the system
-    
+def login_user(username, password):  # noqa: E501
+    """Logs user into the system
+
+     # noqa: E501
+
     :param username: The user name for login
     :type username: str
     :param password: The password for login in clear text
@@ -86,20 +91,22 @@ def login_user(username, password):
     return 'do some magic!'
 
 
-def logout_user():
-    """
-    Logs out current logged in user session
-    
+def logout_user():  # noqa: E501
+    """Logs out current logged in user session
+
+     # noqa: E501
+
 
     :rtype: None
     """
     return 'do some magic!'
 
 
-def update_user(username, body):
-    """
-    Updated user
-    This can only be done by the logged in user.
+def update_user(username, body):  # noqa: E501
+    """Updated user
+
+    This can only be done by the logged in user. # noqa: E501
+
     :param username: name that need to be deleted
     :type username: str
     :param body: Updated user object
@@ -108,5 +115,5 @@ def update_user(username, body):
     :rtype: None
     """
     if connexion.request.is_json:
-        body = User.from_dict(connexion.request.get_json())
+        body = User.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/encoder.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/encoder.py
index 3ff8cad5d72..61ba4721961 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/encoder.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/encoder.py
@@ -1,6 +1,8 @@
-from six import iteritems
-from swagger_server.models.base_model_ import Model
 from connexion.apps.flask_app import FlaskJSONEncoder
+import six
+
+from swagger_server.models.base_model_ import Model
+
 
 class JSONEncoder(FlaskJSONEncoder):
     include_nulls = False
@@ -8,11 +10,11 @@ class JSONEncoder(FlaskJSONEncoder):
     def default(self, o):
         if isinstance(o, Model):
             dikt = {}
-            for attr, _ in iteritems(o.swagger_types):
+            for attr, _ in six.iteritems(o.swagger_types):
                 value = getattr(o, attr)
                 if value is None and not self.include_nulls:
                     continue
                 attr = o.attribute_map[attr]
                 dikt[attr] = value
             return dikt
-        return FlaskJSONEncoder.default(self, o)
\ No newline at end of file
+        return FlaskJSONEncoder.default(self, o)
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/__init__.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/__init__.py
index 6571ad28e0f..fcf8253348d 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/__init__.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/__init__.py
@@ -1,10 +1,11 @@
 # coding: utf-8
 
+# flake8: noqa
 from __future__ import absolute_import
 # import models into model package
-from .api_response import ApiResponse
-from .category import Category
-from .order import Order
-from .pet import Pet
-from .tag import Tag
-from .user import User
+from swagger_server.models.api_response import ApiResponse
+from swagger_server.models.category import Category
+from swagger_server.models.order import Order
+from swagger_server.models.pet import Pet
+from swagger_server.models.tag import Tag
+from swagger_server.models.user import User
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/api_response.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/api_response.py
index c1e51033298..08e4007b9c2 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/api_response.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/api_response.py
@@ -1,28 +1,28 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class ApiResponse(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, code=None, type=None, message=None):  # noqa: E501
+        """ApiResponse - a model defined in Swagger
 
-    def __init__(self, code=None, type=None, message=None):
-        """
-        ApiResponse - a model defined in Swagger
-
-        :param code: The code of this ApiResponse.
+        :param code: The code of this ApiResponse.  # noqa: E501
         :type code: int
-        :param type: The type of this ApiResponse.
+        :param type: The type of this ApiResponse.  # noqa: E501
         :type type: str
-        :param message: The message of this ApiResponse.
+        :param message: The message of this ApiResponse.  # noqa: E501
         :type message: str
         """
         self.swagger_types = {
@@ -43,20 +43,19 @@ class ApiResponse(Model):
 
     @classmethod
     def from_dict(cls, dikt):
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The ApiResponse of this ApiResponse.
+        :return: The ApiResponse of this ApiResponse.  # noqa: E501
         :rtype: ApiResponse
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def code(self):
-        """
-        Gets the code of this ApiResponse.
+        """Gets the code of this ApiResponse.
+
 
         :return: The code of this ApiResponse.
         :rtype: int
@@ -65,8 +64,8 @@ class ApiResponse(Model):
 
     @code.setter
     def code(self, code):
-        """
-        Sets the code of this ApiResponse.
+        """Sets the code of this ApiResponse.
+
 
         :param code: The code of this ApiResponse.
         :type code: int
@@ -76,8 +75,8 @@ class ApiResponse(Model):
 
     @property
     def type(self):
-        """
-        Gets the type of this ApiResponse.
+        """Gets the type of this ApiResponse.
+
 
         :return: The type of this ApiResponse.
         :rtype: str
@@ -86,8 +85,8 @@ class ApiResponse(Model):
 
     @type.setter
     def type(self, type):
-        """
-        Sets the type of this ApiResponse.
+        """Sets the type of this ApiResponse.
+
 
         :param type: The type of this ApiResponse.
         :type type: str
@@ -97,8 +96,8 @@ class ApiResponse(Model):
 
     @property
     def message(self):
-        """
-        Gets the message of this ApiResponse.
+        """Gets the message of this ApiResponse.
+
 
         :return: The message of this ApiResponse.
         :rtype: str
@@ -107,12 +106,11 @@ class ApiResponse(Model):
 
     @message.setter
     def message(self, message):
-        """
-        Sets the message of this ApiResponse.
+        """Sets the message of this ApiResponse.
+
 
         :param message: The message of this ApiResponse.
         :type message: str
         """
 
         self._message = message
-
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/base_model_.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/base_model_.py
index 30a7a03577a..35296d34ca4 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/base_model_.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/base_model_.py
@@ -1,31 +1,32 @@
-from pprint import pformat
-from six import iteritems
-from ..util import deserialize_model
+import pprint
+
+import six
+
+from swagger_server import util
 
 
 class Model(object):
-    # swaggerTypes: The key is attribute name and the value is attribute type.
+    # swaggerTypes: The key is attribute name and the
+    # value is attribute type.
     swagger_types = {}
 
-    # attributeMap: The key is attribute name and the value is json key in definition.
+    # attributeMap: The key is attribute name and the
+    # value is json key in definition.
     attribute_map = {}
 
     @classmethod
     def from_dict(cls, dikt):
-        """
-        Returns the dict as a model
-        """
-        return deserialize_model(dikt, cls)
+        """Returns the dict as a model"""
+        return util.deserialize_model(dikt, cls)
 
     def to_dict(self):
-        """
-        Returns the model properties as a dict
+        """Returns the model properties as a dict
 
         :rtype: dict
         """
         result = {}
 
-        for attr, _ in iteritems(self.swagger_types):
+        for attr, _ in six.iteritems(self.swagger_types):
             value = getattr(self, attr)
             if isinstance(value, list):
                 result[attr] = list(map(
@@ -46,27 +47,20 @@ class Model(object):
         return result
 
     def to_str(self):
-        """
-        Returns the string representation of the model
+        """Returns the string representation of the model
 
         :rtype: str
         """
-        return pformat(self.to_dict())
+        return pprint.pformat(self.to_dict())
 
     def __repr__(self):
-        """
-        For `print` and `pprint`
-        """
+        """For `print` and `pprint`"""
         return self.to_str()
 
     def __eq__(self, other):
-        """
-        Returns true if both objects are equal
-        """
+        """Returns true if both objects are equal"""
         return self.__dict__ == other.__dict__
 
     def __ne__(self, other):
-        """
-        Returns true if both objects are not equal
-        """
-        return not self == other
\ No newline at end of file
+        """Returns true if both objects are not equal"""
+        return not self == other
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/category.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/category.py
index d465845fe11..34aa53d3ce0 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/category.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/category.py
@@ -1,26 +1,26 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class Category(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id=None, name=None):  # noqa: E501
+        """Category - a model defined in Swagger
 
-    def __init__(self, id=None, name=None):
-        """
-        Category - a model defined in Swagger
-
-        :param id: The id of this Category.
+        :param id: The id of this Category.  # noqa: E501
         :type id: long
-        :param name: The name of this Category.
+        :param name: The name of this Category.  # noqa: E501
         :type name: str
         """
         self.swagger_types = {
@@ -38,20 +38,19 @@ class Category(Model):
 
     @classmethod
     def from_dict(cls, dikt):
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Category of this Category.
+        :return: The Category of this Category.  # noqa: E501
         :rtype: Category
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self):
-        """
-        Gets the id of this Category.
+        """Gets the id of this Category.
+
 
         :return: The id of this Category.
         :rtype: long
@@ -60,8 +59,8 @@ class Category(Model):
 
     @id.setter
     def id(self, id):
-        """
-        Sets the id of this Category.
+        """Sets the id of this Category.
+
 
         :param id: The id of this Category.
         :type id: long
@@ -71,8 +70,8 @@ class Category(Model):
 
     @property
     def name(self):
-        """
-        Gets the name of this Category.
+        """Gets the name of this Category.
+
 
         :return: The name of this Category.
         :rtype: str
@@ -81,12 +80,11 @@ class Category(Model):
 
     @name.setter
     def name(self, name):
-        """
-        Sets the name of this Category.
+        """Sets the name of this Category.
+
 
         :param name: The name of this Category.
         :type name: str
         """
 
         self._name = name
-
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/order.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/order.py
index fefe4cb8c5f..7b7f5f0645f 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/order.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/order.py
@@ -1,34 +1,34 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class Order(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id=None, pet_id=None, quantity=None, ship_date=None, status=None, complete=False):  # noqa: E501
+        """Order - a model defined in Swagger
 
-    def __init__(self, id=None, pet_id=None, quantity=None, ship_date=None, status=None, complete=False):
-        """
-        Order - a model defined in Swagger
-
-        :param id: The id of this Order.
+        :param id: The id of this Order.  # noqa: E501
         :type id: long
-        :param pet_id: The pet_id of this Order.
+        :param pet_id: The pet_id of this Order.  # noqa: E501
         :type pet_id: long
-        :param quantity: The quantity of this Order.
+        :param quantity: The quantity of this Order.  # noqa: E501
         :type quantity: int
-        :param ship_date: The ship_date of this Order.
+        :param ship_date: The ship_date of this Order.  # noqa: E501
         :type ship_date: datetime
-        :param status: The status of this Order.
+        :param status: The status of this Order.  # noqa: E501
         :type status: str
-        :param complete: The complete of this Order.
+        :param complete: The complete of this Order.  # noqa: E501
         :type complete: bool
         """
         self.swagger_types = {
@@ -58,20 +58,19 @@ class Order(Model):
 
     @classmethod
     def from_dict(cls, dikt):
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Order of this Order.
+        :return: The Order of this Order.  # noqa: E501
         :rtype: Order
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self):
-        """
-        Gets the id of this Order.
+        """Gets the id of this Order.
+
 
         :return: The id of this Order.
         :rtype: long
@@ -80,8 +79,8 @@ class Order(Model):
 
     @id.setter
     def id(self, id):
-        """
-        Sets the id of this Order.
+        """Sets the id of this Order.
+
 
         :param id: The id of this Order.
         :type id: long
@@ -91,8 +90,8 @@ class Order(Model):
 
     @property
     def pet_id(self):
-        """
-        Gets the pet_id of this Order.
+        """Gets the pet_id of this Order.
+
 
         :return: The pet_id of this Order.
         :rtype: long
@@ -101,8 +100,8 @@ class Order(Model):
 
     @pet_id.setter
     def pet_id(self, pet_id):
-        """
-        Sets the pet_id of this Order.
+        """Sets the pet_id of this Order.
+
 
         :param pet_id: The pet_id of this Order.
         :type pet_id: long
@@ -112,8 +111,8 @@ class Order(Model):
 
     @property
     def quantity(self):
-        """
-        Gets the quantity of this Order.
+        """Gets the quantity of this Order.
+
 
         :return: The quantity of this Order.
         :rtype: int
@@ -122,8 +121,8 @@ class Order(Model):
 
     @quantity.setter
     def quantity(self, quantity):
-        """
-        Sets the quantity of this Order.
+        """Sets the quantity of this Order.
+
 
         :param quantity: The quantity of this Order.
         :type quantity: int
@@ -133,8 +132,8 @@ class Order(Model):
 
     @property
     def ship_date(self):
-        """
-        Gets the ship_date of this Order.
+        """Gets the ship_date of this Order.
+
 
         :return: The ship_date of this Order.
         :rtype: datetime
@@ -143,8 +142,8 @@ class Order(Model):
 
     @ship_date.setter
     def ship_date(self, ship_date):
-        """
-        Sets the ship_date of this Order.
+        """Sets the ship_date of this Order.
+
 
         :param ship_date: The ship_date of this Order.
         :type ship_date: datetime
@@ -154,9 +153,9 @@ class Order(Model):
 
     @property
     def status(self):
-        """
-        Gets the status of this Order.
-        Order Status
+        """Gets the status of this Order.
+
+        Order Status  # noqa: E501
 
         :return: The status of this Order.
         :rtype: str
@@ -165,14 +164,14 @@ class Order(Model):
 
     @status.setter
     def status(self, status):
-        """
-        Sets the status of this Order.
-        Order Status
+        """Sets the status of this Order.
+
+        Order Status  # noqa: E501
 
         :param status: The status of this Order.
         :type status: str
         """
-        allowed_values = ["placed", "approved", "delivered"]
+        allowed_values = ["placed", "approved", "delivered"]  # noqa: E501
         if status not in allowed_values:
             raise ValueError(
                 "Invalid value for `status` ({0}), must be one of {1}"
@@ -183,8 +182,8 @@ class Order(Model):
 
     @property
     def complete(self):
-        """
-        Gets the complete of this Order.
+        """Gets the complete of this Order.
+
 
         :return: The complete of this Order.
         :rtype: bool
@@ -193,12 +192,11 @@ class Order(Model):
 
     @complete.setter
     def complete(self, complete):
-        """
-        Sets the complete of this Order.
+        """Sets the complete of this Order.
+
 
         :param complete: The complete of this Order.
         :type complete: bool
         """
 
         self._complete = complete
-
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/pet.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/pet.py
index 35dac42dc45..52ef5f7e9d3 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/pet.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/pet.py
@@ -1,36 +1,36 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from swagger_server.models.category import Category
-from swagger_server.models.tag import Tag
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server.models.category import Category  # noqa: E501
+from swagger_server.models.tag import Tag  # noqa: E501
+from swagger_server import util
 
 
 class Pet(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id=None, category=None, name=None, photo_urls=None, tags=None, status=None):  # noqa: E501
+        """Pet - a model defined in Swagger
 
-    def __init__(self, id=None, category=None, name=None, photo_urls=None, tags=None, status=None):
-        """
-        Pet - a model defined in Swagger
-
-        :param id: The id of this Pet.
+        :param id: The id of this Pet.  # noqa: E501
         :type id: long
-        :param category: The category of this Pet.
+        :param category: The category of this Pet.  # noqa: E501
         :type category: Category
-        :param name: The name of this Pet.
+        :param name: The name of this Pet.  # noqa: E501
         :type name: str
-        :param photo_urls: The photo_urls of this Pet.
+        :param photo_urls: The photo_urls of this Pet.  # noqa: E501
         :type photo_urls: List[str]
-        :param tags: The tags of this Pet.
+        :param tags: The tags of this Pet.  # noqa: E501
         :type tags: List[Tag]
-        :param status: The status of this Pet.
+        :param status: The status of this Pet.  # noqa: E501
         :type status: str
         """
         self.swagger_types = {
@@ -60,20 +60,19 @@ class Pet(Model):
 
     @classmethod
     def from_dict(cls, dikt):
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Pet of this Pet.
+        :return: The Pet of this Pet.  # noqa: E501
         :rtype: Pet
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self):
-        """
-        Gets the id of this Pet.
+        """Gets the id of this Pet.
+
 
         :return: The id of this Pet.
         :rtype: long
@@ -82,8 +81,8 @@ class Pet(Model):
 
     @id.setter
     def id(self, id):
-        """
-        Sets the id of this Pet.
+        """Sets the id of this Pet.
+
 
         :param id: The id of this Pet.
         :type id: long
@@ -93,8 +92,8 @@ class Pet(Model):
 
     @property
     def category(self):
-        """
-        Gets the category of this Pet.
+        """Gets the category of this Pet.
+
 
         :return: The category of this Pet.
         :rtype: Category
@@ -103,8 +102,8 @@ class Pet(Model):
 
     @category.setter
     def category(self, category):
-        """
-        Sets the category of this Pet.
+        """Sets the category of this Pet.
+
 
         :param category: The category of this Pet.
         :type category: Category
@@ -114,8 +113,8 @@ class Pet(Model):
 
     @property
     def name(self):
-        """
-        Gets the name of this Pet.
+        """Gets the name of this Pet.
+
 
         :return: The name of this Pet.
         :rtype: str
@@ -124,21 +123,21 @@ class Pet(Model):
 
     @name.setter
     def name(self, name):
-        """
-        Sets the name of this Pet.
+        """Sets the name of this Pet.
+
 
         :param name: The name of this Pet.
         :type name: str
         """
         if name is None:
-            raise ValueError("Invalid value for `name`, must not be `None`")
+            raise ValueError("Invalid value for `name`, must not be `None`")  # noqa: E501
 
         self._name = name
 
     @property
     def photo_urls(self):
-        """
-        Gets the photo_urls of this Pet.
+        """Gets the photo_urls of this Pet.
+
 
         :return: The photo_urls of this Pet.
         :rtype: List[str]
@@ -147,21 +146,21 @@ class Pet(Model):
 
     @photo_urls.setter
     def photo_urls(self, photo_urls):
-        """
-        Sets the photo_urls of this Pet.
+        """Sets the photo_urls of this Pet.
+
 
         :param photo_urls: The photo_urls of this Pet.
         :type photo_urls: List[str]
         """
         if photo_urls is None:
-            raise ValueError("Invalid value for `photo_urls`, must not be `None`")
+            raise ValueError("Invalid value for `photo_urls`, must not be `None`")  # noqa: E501
 
         self._photo_urls = photo_urls
 
     @property
     def tags(self):
-        """
-        Gets the tags of this Pet.
+        """Gets the tags of this Pet.
+
 
         :return: The tags of this Pet.
         :rtype: List[Tag]
@@ -170,8 +169,8 @@ class Pet(Model):
 
     @tags.setter
     def tags(self, tags):
-        """
-        Sets the tags of this Pet.
+        """Sets the tags of this Pet.
+
 
         :param tags: The tags of this Pet.
         :type tags: List[Tag]
@@ -181,9 +180,9 @@ class Pet(Model):
 
     @property
     def status(self):
-        """
-        Gets the status of this Pet.
-        pet status in the store
+        """Gets the status of this Pet.
+
+        pet status in the store  # noqa: E501
 
         :return: The status of this Pet.
         :rtype: str
@@ -192,14 +191,14 @@ class Pet(Model):
 
     @status.setter
     def status(self, status):
-        """
-        Sets the status of this Pet.
-        pet status in the store
+        """Sets the status of this Pet.
+
+        pet status in the store  # noqa: E501
 
         :param status: The status of this Pet.
         :type status: str
         """
-        allowed_values = ["available", "pending", "sold"]
+        allowed_values = ["available", "pending", "sold"]  # noqa: E501
         if status not in allowed_values:
             raise ValueError(
                 "Invalid value for `status` ({0}), must be one of {1}"
@@ -207,4 +206,3 @@ class Pet(Model):
             )
 
         self._status = status
-
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/tag.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/tag.py
index 0933d44d0b1..d26d435242e 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/tag.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/tag.py
@@ -1,26 +1,26 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class Tag(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id=None, name=None):  # noqa: E501
+        """Tag - a model defined in Swagger
 
-    def __init__(self, id=None, name=None):
-        """
-        Tag - a model defined in Swagger
-
-        :param id: The id of this Tag.
+        :param id: The id of this Tag.  # noqa: E501
         :type id: long
-        :param name: The name of this Tag.
+        :param name: The name of this Tag.  # noqa: E501
         :type name: str
         """
         self.swagger_types = {
@@ -38,20 +38,19 @@ class Tag(Model):
 
     @classmethod
     def from_dict(cls, dikt):
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Tag of this Tag.
+        :return: The Tag of this Tag.  # noqa: E501
         :rtype: Tag
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self):
-        """
-        Gets the id of this Tag.
+        """Gets the id of this Tag.
+
 
         :return: The id of this Tag.
         :rtype: long
@@ -60,8 +59,8 @@ class Tag(Model):
 
     @id.setter
     def id(self, id):
-        """
-        Sets the id of this Tag.
+        """Sets the id of this Tag.
+
 
         :param id: The id of this Tag.
         :type id: long
@@ -71,8 +70,8 @@ class Tag(Model):
 
     @property
     def name(self):
-        """
-        Gets the name of this Tag.
+        """Gets the name of this Tag.
+
 
         :return: The name of this Tag.
         :rtype: str
@@ -81,12 +80,11 @@ class Tag(Model):
 
     @name.setter
     def name(self, name):
-        """
-        Sets the name of this Tag.
+        """Sets the name of this Tag.
+
 
         :param name: The name of this Tag.
         :type name: str
         """
 
         self._name = name
-
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/user.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/user.py
index eddf5ef92ef..84956ff2663 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/models/user.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/models/user.py
@@ -1,38 +1,38 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class User(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id=None, username=None, first_name=None, last_name=None, email=None, password=None, phone=None, user_status=None):  # noqa: E501
+        """User - a model defined in Swagger
 
-    def __init__(self, id=None, username=None, first_name=None, last_name=None, email=None, password=None, phone=None, user_status=None):
-        """
-        User - a model defined in Swagger
-
-        :param id: The id of this User.
+        :param id: The id of this User.  # noqa: E501
         :type id: long
-        :param username: The username of this User.
+        :param username: The username of this User.  # noqa: E501
         :type username: str
-        :param first_name: The first_name of this User.
+        :param first_name: The first_name of this User.  # noqa: E501
         :type first_name: str
-        :param last_name: The last_name of this User.
+        :param last_name: The last_name of this User.  # noqa: E501
         :type last_name: str
-        :param email: The email of this User.
+        :param email: The email of this User.  # noqa: E501
         :type email: str
-        :param password: The password of this User.
+        :param password: The password of this User.  # noqa: E501
         :type password: str
-        :param phone: The phone of this User.
+        :param phone: The phone of this User.  # noqa: E501
         :type phone: str
-        :param user_status: The user_status of this User.
+        :param user_status: The user_status of this User.  # noqa: E501
         :type user_status: int
         """
         self.swagger_types = {
@@ -68,20 +68,19 @@ class User(Model):
 
     @classmethod
     def from_dict(cls, dikt):
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The User of this User.
+        :return: The User of this User.  # noqa: E501
         :rtype: User
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self):
-        """
-        Gets the id of this User.
+        """Gets the id of this User.
+
 
         :return: The id of this User.
         :rtype: long
@@ -90,8 +89,8 @@ class User(Model):
 
     @id.setter
     def id(self, id):
-        """
-        Sets the id of this User.
+        """Sets the id of this User.
+
 
         :param id: The id of this User.
         :type id: long
@@ -101,8 +100,8 @@ class User(Model):
 
     @property
     def username(self):
-        """
-        Gets the username of this User.
+        """Gets the username of this User.
+
 
         :return: The username of this User.
         :rtype: str
@@ -111,8 +110,8 @@ class User(Model):
 
     @username.setter
     def username(self, username):
-        """
-        Sets the username of this User.
+        """Sets the username of this User.
+
 
         :param username: The username of this User.
         :type username: str
@@ -122,8 +121,8 @@ class User(Model):
 
     @property
     def first_name(self):
-        """
-        Gets the first_name of this User.
+        """Gets the first_name of this User.
+
 
         :return: The first_name of this User.
         :rtype: str
@@ -132,8 +131,8 @@ class User(Model):
 
     @first_name.setter
     def first_name(self, first_name):
-        """
-        Sets the first_name of this User.
+        """Sets the first_name of this User.
+
 
         :param first_name: The first_name of this User.
         :type first_name: str
@@ -143,8 +142,8 @@ class User(Model):
 
     @property
     def last_name(self):
-        """
-        Gets the last_name of this User.
+        """Gets the last_name of this User.
+
 
         :return: The last_name of this User.
         :rtype: str
@@ -153,8 +152,8 @@ class User(Model):
 
     @last_name.setter
     def last_name(self, last_name):
-        """
-        Sets the last_name of this User.
+        """Sets the last_name of this User.
+
 
         :param last_name: The last_name of this User.
         :type last_name: str
@@ -164,8 +163,8 @@ class User(Model):
 
     @property
     def email(self):
-        """
-        Gets the email of this User.
+        """Gets the email of this User.
+
 
         :return: The email of this User.
         :rtype: str
@@ -174,8 +173,8 @@ class User(Model):
 
     @email.setter
     def email(self, email):
-        """
-        Sets the email of this User.
+        """Sets the email of this User.
+
 
         :param email: The email of this User.
         :type email: str
@@ -185,8 +184,8 @@ class User(Model):
 
     @property
     def password(self):
-        """
-        Gets the password of this User.
+        """Gets the password of this User.
+
 
         :return: The password of this User.
         :rtype: str
@@ -195,8 +194,8 @@ class User(Model):
 
     @password.setter
     def password(self, password):
-        """
-        Sets the password of this User.
+        """Sets the password of this User.
+
 
         :param password: The password of this User.
         :type password: str
@@ -206,8 +205,8 @@ class User(Model):
 
     @property
     def phone(self):
-        """
-        Gets the phone of this User.
+        """Gets the phone of this User.
+
 
         :return: The phone of this User.
         :rtype: str
@@ -216,8 +215,8 @@ class User(Model):
 
     @phone.setter
     def phone(self, phone):
-        """
-        Sets the phone of this User.
+        """Sets the phone of this User.
+
 
         :param phone: The phone of this User.
         :type phone: str
@@ -227,9 +226,9 @@ class User(Model):
 
     @property
     def user_status(self):
-        """
-        Gets the user_status of this User.
-        User Status
+        """Gets the user_status of this User.
+
+        User Status  # noqa: E501
 
         :return: The user_status of this User.
         :rtype: int
@@ -238,13 +237,12 @@ class User(Model):
 
     @user_status.setter
     def user_status(self, user_status):
-        """
-        Sets the user_status of this User.
-        User Status
+        """Sets the user_status of this User.
+
+        User Status  # noqa: E501
 
         :param user_status: The user_status of this User.
         :type user_status: int
         """
 
         self._user_status = user_status
-
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/swagger/swagger.yaml b/samples/server/petstore/flaskConnexion-python2/swagger_server/swagger/swagger.yaml
index ba2a870047d..28b7a179620 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/swagger/swagger.yaml
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/swagger/swagger.yaml
@@ -108,11 +108,11 @@ paths:
         type: "array"
         items:
           type: "string"
+          default: "available"
           enum:
           - "available"
           - "pending"
           - "sold"
-          default: "available"
         collectionFormat: "csv"
       responses:
         200:
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/__init__.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/__init__.py
index 77b10c3a012..644506301ce 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/__init__.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/__init__.py
@@ -1,8 +1,10 @@
-from flask_testing import TestCase
-from ..encoder import JSONEncoder
-import connexion
 import logging
 
+import connexion
+from flask_testing import TestCase
+
+from swagger_server.encoder import JSONEncoder
+
 
 class BaseTestCase(TestCase):
 
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_pet_controller.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_pet_controller.py
index b99269a991a..fb4c34ea3e1 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_pet_controller.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_pet_controller.py
@@ -2,115 +2,124 @@
 
 from __future__ import absolute_import
 
-from swagger_server.models.api_response import ApiResponse
-from swagger_server.models.pet import Pet
-from . import BaseTestCase
-from six import BytesIO
 from flask import json
+from six import BytesIO
+
+from swagger_server.models.api_response import ApiResponse  # noqa: E501
+from swagger_server.models.pet import Pet  # noqa: E501
+from swagger_server.test import BaseTestCase
 
 
 class TestPetController(BaseTestCase):
-    """ PetController integration test stubs """
+    """PetController integration test stubs"""
 
     def test_add_pet(self):
-        """
-        Test case for add_pet
+        """Test case for add_pet
 
         Add a new pet to the store
         """
         body = Pet()
-        response = self.client.open('/v2/pet',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_delete_pet(self):
-        """
-        Test case for delete_pet
+        """Test case for delete_pet
 
         Deletes a pet
         """
         headers = [('api_key', 'api_key_example')]
-        response = self.client.open('/v2/pet/{petId}'.format(petId=789),
-                                    method='DELETE',
-                                    headers=headers)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}'.format(petId=789),
+            method='DELETE',
+            headers=headers)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_find_pets_by_status(self):
-        """
-        Test case for find_pets_by_status
+        """Test case for find_pets_by_status
 
         Finds Pets by status
         """
         query_string = [('status', 'available')]
-        response = self.client.open('/v2/pet/findByStatus',
-                                    method='GET',
-                                    query_string=query_string)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/findByStatus',
+            method='GET',
+            query_string=query_string)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_find_pets_by_tags(self):
-        """
-        Test case for find_pets_by_tags
+        """Test case for find_pets_by_tags
 
         Finds Pets by tags
         """
         query_string = [('tags', 'tags_example')]
-        response = self.client.open('/v2/pet/findByTags',
-                                    method='GET',
-                                    query_string=query_string)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/findByTags',
+            method='GET',
+            query_string=query_string)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_pet_by_id(self):
-        """
-        Test case for get_pet_by_id
+        """Test case for get_pet_by_id
 
         Find pet by ID
         """
-        response = self.client.open('/v2/pet/{petId}'.format(petId=789),
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}'.format(petId=789),
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_update_pet(self):
-        """
-        Test case for update_pet
+        """Test case for update_pet
 
         Update an existing pet
         """
         body = Pet()
-        response = self.client.open('/v2/pet',
-                                    method='PUT',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet',
+            method='PUT',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_update_pet_with_form(self):
-        """
-        Test case for update_pet_with_form
+        """Test case for update_pet_with_form
 
         Updates a pet in the store with form data
         """
         data = dict(name='name_example',
                     status='status_example')
-        response = self.client.open('/v2/pet/{petId}'.format(petId=789),
-                                    method='POST',
-                                    data=data,
-                                    content_type='application/x-www-form-urlencoded')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}'.format(petId=789),
+            method='POST',
+            data=data,
+            content_type='application/x-www-form-urlencoded')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_upload_file(self):
-        """
-        Test case for upload_file
+        """Test case for upload_file
 
         uploads an image
         """
         data = dict(additionalMetadata='additionalMetadata_example',
                     file=(BytesIO(b'some file data'), 'file.txt'))
-        response = self.client.open('/v2/pet/{petId}/uploadImage'.format(petId=789),
-                                    method='POST',
-                                    data=data,
-                                    content_type='multipart/form-data')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}/uploadImage'.format(petId=789),
+            method='POST',
+            data=data,
+            content_type='multipart/form-data')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
 
 if __name__ == '__main__':
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_store_controller.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_store_controller.py
index 0a5360b4e25..854e18600fc 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_store_controller.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_store_controller.py
@@ -2,57 +2,62 @@
 
 from __future__ import absolute_import
 
-from swagger_server.models.order import Order
-from . import BaseTestCase
-from six import BytesIO
 from flask import json
+from six import BytesIO
+
+from swagger_server.models.order import Order  # noqa: E501
+from swagger_server.test import BaseTestCase
 
 
 class TestStoreController(BaseTestCase):
-    """ StoreController integration test stubs """
+    """StoreController integration test stubs"""
 
     def test_delete_order(self):
-        """
-        Test case for delete_order
+        """Test case for delete_order
 
         Delete purchase order by ID
         """
-        response = self.client.open('/v2/store/order/{orderId}'.format(orderId='orderId_example'),
-                                    method='DELETE')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/order/{orderId}'.format(orderId='orderId_example'),
+            method='DELETE')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_inventory(self):
-        """
-        Test case for get_inventory
+        """Test case for get_inventory
 
         Returns pet inventories by status
         """
-        response = self.client.open('/v2/store/inventory',
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/inventory',
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_order_by_id(self):
-        """
-        Test case for get_order_by_id
+        """Test case for get_order_by_id
 
         Find purchase order by ID
         """
-        response = self.client.open('/v2/store/order/{orderId}'.format(orderId=5),
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/order/{orderId}'.format(orderId=5),
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_place_order(self):
-        """
-        Test case for place_order
+        """Test case for place_order
 
         Place an order for a pet
         """
         body = Order()
-        response = self.client.open('/v2/store/order',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/order',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
 
 if __name__ == '__main__':
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_user_controller.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_user_controller.py
index 867de3c0150..30e1885afab 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_user_controller.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/test/test_user_controller.py
@@ -2,109 +2,118 @@
 
 from __future__ import absolute_import
 
-from swagger_server.models.user import User
-from . import BaseTestCase
-from six import BytesIO
 from flask import json
+from six import BytesIO
+
+from swagger_server.models.user import User  # noqa: E501
+from swagger_server.test import BaseTestCase
 
 
 class TestUserController(BaseTestCase):
-    """ UserController integration test stubs """
+    """UserController integration test stubs"""
 
     def test_create_user(self):
-        """
-        Test case for create_user
+        """Test case for create_user
 
         Create user
         """
         body = User()
-        response = self.client.open('/v2/user',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_create_users_with_array_input(self):
-        """
-        Test case for create_users_with_array_input
+        """Test case for create_users_with_array_input
 
         Creates list of users with given input array
         """
         body = [User()]
-        response = self.client.open('/v2/user/createWithArray',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/createWithArray',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_create_users_with_list_input(self):
-        """
-        Test case for create_users_with_list_input
+        """Test case for create_users_with_list_input
 
         Creates list of users with given input array
         """
         body = [User()]
-        response = self.client.open('/v2/user/createWithList',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/createWithList',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_delete_user(self):
-        """
-        Test case for delete_user
+        """Test case for delete_user
 
         Delete user
         """
-        response = self.client.open('/v2/user/{username}'.format(username='username_example'),
-                                    method='DELETE')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/{username}'.format(username='username_example'),
+            method='DELETE')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_user_by_name(self):
-        """
-        Test case for get_user_by_name
+        """Test case for get_user_by_name
 
         Get user by user name
         """
-        response = self.client.open('/v2/user/{username}'.format(username='username_example'),
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/{username}'.format(username='username_example'),
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_login_user(self):
-        """
-        Test case for login_user
+        """Test case for login_user
 
         Logs user into the system
         """
         query_string = [('username', 'username_example'),
                         ('password', 'password_example')]
-        response = self.client.open('/v2/user/login',
-                                    method='GET',
-                                    query_string=query_string)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/login',
+            method='GET',
+            query_string=query_string)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_logout_user(self):
-        """
-        Test case for logout_user
+        """Test case for logout_user
 
         Logs out current logged in user session
         """
-        response = self.client.open('/v2/user/logout',
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/logout',
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_update_user(self):
-        """
-        Test case for update_user
+        """Test case for update_user
 
         Updated user
         """
         body = User()
-        response = self.client.open('/v2/user/{username}'.format(username='username_example'),
-                                    method='PUT',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/{username}'.format(username='username_example'),
+            method='PUT',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
 
 if __name__ == '__main__':
diff --git a/samples/server/petstore/flaskConnexion-python2/swagger_server/util.py b/samples/server/petstore/flaskConnexion-python2/swagger_server/util.py
index 40c72d43ebd..b0576ef9594 100644
--- a/samples/server/petstore/flaskConnexion-python2/swagger_server/util.py
+++ b/samples/server/petstore/flaskConnexion-python2/swagger_server/util.py
@@ -1,11 +1,11 @@
-from typing import GenericMeta
-from datetime import datetime, date
-from six import integer_types, iteritems
+import datetime
+
+import six
+import typing
 
 
 def _deserialize(data, klass):
-    """
-    Deserializes dict, list, str into an object.
+    """Deserializes dict, list, str into an object.
 
     :param data: dict, list or str.
     :param klass: class literal, or string of class name.
@@ -15,15 +15,15 @@ def _deserialize(data, klass):
     if data is None:
         return None
 
-    if klass in integer_types or klass in (float, str, bool):
+    if klass in six.integer_types or klass in (float, str, bool):
         return _deserialize_primitive(data, klass)
     elif klass == object:
         return _deserialize_object(data)
-    elif klass == date:
+    elif klass == datetime.date:
         return deserialize_date(data)
-    elif klass == datetime:
+    elif klass == datetime.datetime:
         return deserialize_datetime(data)
-    elif type(klass) == GenericMeta:
+    elif type(klass) == typing.GenericMeta:
         if klass.__extra__ == list:
             return _deserialize_list(data, klass.__args__[0])
         if klass.__extra__ == dict:
@@ -33,8 +33,7 @@ def _deserialize(data, klass):
 
 
 def _deserialize_primitive(data, klass):
-    """
-    Deserializes to primitive type.
+    """Deserializes to primitive type.
 
     :param data: data to deserialize.
     :param klass: class literal.
@@ -52,8 +51,7 @@ def _deserialize_primitive(data, klass):
 
 
 def _deserialize_object(value):
-    """
-    Return a original value.
+    """Return a original value.
 
     :return: object.
     """
@@ -61,8 +59,7 @@ def _deserialize_object(value):
 
 
 def deserialize_date(string):
-    """
-    Deserializes string to date.
+    """Deserializes string to date.
 
     :param string: str.
     :type string: str
@@ -77,8 +74,7 @@ def deserialize_date(string):
 
 
 def deserialize_datetime(string):
-    """
-    Deserializes string to datetime.
+    """Deserializes string to datetime.
 
     The string should be in iso8601 datetime format.
 
@@ -95,8 +91,7 @@ def deserialize_datetime(string):
 
 
 def deserialize_model(data, klass):
-    """
-    Deserializes list or dict to model.
+    """Deserializes list or dict to model.
 
     :param data: dict, list.
     :type data: dict | list
@@ -108,7 +103,7 @@ def deserialize_model(data, klass):
     if not instance.swagger_types:
         return data
 
-    for attr, attr_type in iteritems(instance.swagger_types):
+    for attr, attr_type in six.iteritems(instance.swagger_types):
         if data is not None \
                 and instance.attribute_map[attr] in data \
                 and isinstance(data, (list, dict)):
@@ -119,8 +114,7 @@ def deserialize_model(data, klass):
 
 
 def _deserialize_list(data, boxed_type):
-    """
-    Deserializes a list and its elements.
+    """Deserializes a list and its elements.
 
     :param data: list to deserialize.
     :type data: list
@@ -133,10 +127,8 @@ def _deserialize_list(data, boxed_type):
             for sub_data in data]
 
 
-
 def _deserialize_dict(data, boxed_type):
-    """
-    Deserializes a dict and its elements.
+    """Deserializes a dict and its elements.
 
     :param data: dict to deserialize.
     :type data: dict
@@ -146,4 +138,4 @@ def _deserialize_dict(data, boxed_type):
     :rtype: dict
     """
     return {k: _deserialize(v, boxed_type)
-            for k, v in iteritems(data)}
+            for k, v in six.iteritems(data)}
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/__main__.py b/samples/server/petstore/flaskConnexion/swagger_server/__main__.py
index 6cc3e2d9511..734cc4b3dd2 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/__main__.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/__main__.py
@@ -1,13 +1,14 @@
 #!/usr/bin/env python3
 
 import connexion
-from .encoder import JSONEncoder
+
+from swagger_server import encoder
 
 
 def main():
     app = connexion.App(__name__, specification_dir='./swagger/')
-    app.app.json_encoder = JSONEncoder
-    app.add_api('swagger.yaml', arguments={'title': 'This is a sample server Petstore server.  You can find out more about Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net, #swagger](http://swagger.io/irc/).  For this sample, you can use the api key &#x60;special-key&#x60; to test the authorization filters.'})
+    app.app.json_encoder = encoder.JSONEncoder
+    app.add_api('swagger.yaml', arguments={'title': 'Swagger Petstore'})
     app.run(port=8080)
 
 
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/controllers/pet_controller.py b/samples/server/petstore/flaskConnexion/swagger_server/controllers/pet_controller.py
index 5a999aae88f..5de865c908a 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/controllers/pet_controller.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/controllers/pet_controller.py
@@ -1,30 +1,31 @@
 import connexion
-from swagger_server.models.api_response import ApiResponse
-from swagger_server.models.pet import Pet
-from datetime import date, datetime
-from typing import List, Dict
-from six import iteritems
-from ..util import deserialize_date, deserialize_datetime
+import six
+
+from swagger_server.models.api_response import ApiResponse  # noqa: E501
+from swagger_server.models.pet import Pet  # noqa: E501
+from swagger_server import util
 
 
-def add_pet(body):
-    """
-    Add a new pet to the store
-    
+def add_pet(body):  # noqa: E501
+    """Add a new pet to the store
+
+     # noqa: E501
+
     :param body: Pet object that needs to be added to the store
     :type body: dict | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = Pet.from_dict(connexion.request.get_json())
+        body = Pet.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
 
 
-def delete_pet(petId, api_key=None):
-    """
-    Deletes a pet
-    
+def delete_pet(petId, api_key=None):  # noqa: E501
+    """Deletes a pet
+
+     # noqa: E501
+
     :param petId: Pet id to delete
     :type petId: int
     :param api_key: 
@@ -35,10 +36,11 @@ def delete_pet(petId, api_key=None):
     return 'do some magic!'
 
 
-def find_pets_by_status(status):
-    """
-    Finds Pets by status
-    Multiple status values can be provided with comma separated strings
+def find_pets_by_status(status):  # noqa: E501
+    """Finds Pets by status
+
+    Multiple status values can be provided with comma separated strings # noqa: E501
+
     :param status: Status values that need to be considered for filter
     :type status: List[str]
 
@@ -47,10 +49,11 @@ def find_pets_by_status(status):
     return 'do some magic!'
 
 
-def find_pets_by_tags(tags):
-    """
-    Finds Pets by tags
-    Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.
+def find_pets_by_tags(tags):  # noqa: E501
+    """Finds Pets by tags
+
+    Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing. # noqa: E501
+
     :param tags: Tags to filter by
     :type tags: List[str]
 
@@ -59,10 +62,11 @@ def find_pets_by_tags(tags):
     return 'do some magic!'
 
 
-def get_pet_by_id(petId):
-    """
-    Find pet by ID
-    Returns a single pet
+def get_pet_by_id(petId):  # noqa: E501
+    """Find pet by ID
+
+    Returns a single pet # noqa: E501
+
     :param petId: ID of pet to return
     :type petId: int
 
@@ -71,24 +75,26 @@ def get_pet_by_id(petId):
     return 'do some magic!'
 
 
-def update_pet(body):
-    """
-    Update an existing pet
-    
+def update_pet(body):  # noqa: E501
+    """Update an existing pet
+
+     # noqa: E501
+
     :param body: Pet object that needs to be added to the store
     :type body: dict | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = Pet.from_dict(connexion.request.get_json())
+        body = Pet.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
 
 
-def update_pet_with_form(petId, name=None, status=None):
-    """
-    Updates a pet in the store with form data
-    
+def update_pet_with_form(petId, name=None, status=None):  # noqa: E501
+    """Updates a pet in the store with form data
+
+     # noqa: E501
+
     :param petId: ID of pet that needs to be updated
     :type petId: int
     :param name: Updated name of the pet
@@ -101,10 +107,11 @@ def update_pet_with_form(petId, name=None, status=None):
     return 'do some magic!'
 
 
-def upload_file(petId, additionalMetadata=None, file=None):
-    """
-    uploads an image
-    
+def upload_file(petId, additionalMetadata=None, file=None):  # noqa: E501
+    """uploads an image
+
+     # noqa: E501
+
     :param petId: ID of pet to update
     :type petId: int
     :param additionalMetadata: Additional data to pass to server
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/controllers/store_controller.py b/samples/server/petstore/flaskConnexion/swagger_server/controllers/store_controller.py
index 0cdcaf445dc..eae3546c21e 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/controllers/store_controller.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/controllers/store_controller.py
@@ -1,15 +1,15 @@
 import connexion
-from swagger_server.models.order import Order
-from datetime import date, datetime
-from typing import List, Dict
-from six import iteritems
-from ..util import deserialize_date, deserialize_datetime
+import six
+
+from swagger_server.models.order import Order  # noqa: E501
+from swagger_server import util
 
 
-def delete_order(orderId):
-    """
-    Delete purchase order by ID
-    For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors
+def delete_order(orderId):  # noqa: E501
+    """Delete purchase order by ID
+
+    For valid response try integer IDs with value &lt; 1000. Anything above 1000 or nonintegers will generate API errors # noqa: E501
+
     :param orderId: ID of the order that needs to be deleted
     :type orderId: str
 
@@ -18,20 +18,22 @@ def delete_order(orderId):
     return 'do some magic!'
 
 
-def get_inventory():
-    """
-    Returns pet inventories by status
-    Returns a map of status codes to quantities
+def get_inventory():  # noqa: E501
+    """Returns pet inventories by status
+
+    Returns a map of status codes to quantities # noqa: E501
+
 
     :rtype: Dict[str, int]
     """
     return 'do some magic!'
 
 
-def get_order_by_id(orderId):
-    """
-    Find purchase order by ID
-    For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions
+def get_order_by_id(orderId):  # noqa: E501
+    """Find purchase order by ID
+
+    For valid response try integer IDs with value &lt;&#x3D; 5 or &gt; 10. Other values will generated exceptions # noqa: E501
+
     :param orderId: ID of pet that needs to be fetched
     :type orderId: int
 
@@ -40,15 +42,16 @@ def get_order_by_id(orderId):
     return 'do some magic!'
 
 
-def place_order(body):
-    """
-    Place an order for a pet
-    
+def place_order(body):  # noqa: E501
+    """Place an order for a pet
+
+     # noqa: E501
+
     :param body: order placed for purchasing the pet
     :type body: dict | bytes
 
     :rtype: Order
     """
     if connexion.request.is_json:
-        body = Order.from_dict(connexion.request.get_json())
+        body = Order.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/controllers/user_controller.py b/samples/server/petstore/flaskConnexion/swagger_server/controllers/user_controller.py
index 9a88626c5b8..c7c3ee3519a 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/controllers/user_controller.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/controllers/user_controller.py
@@ -1,57 +1,60 @@
 import connexion
-from swagger_server.models.user import User
-from datetime import date, datetime
-from typing import List, Dict
-from six import iteritems
-from ..util import deserialize_date, deserialize_datetime
+import six
+
+from swagger_server.models.user import User  # noqa: E501
+from swagger_server import util
 
 
-def create_user(body):
-    """
-    Create user
-    This can only be done by the logged in user.
+def create_user(body):  # noqa: E501
+    """Create user
+
+    This can only be done by the logged in user. # noqa: E501
+
     :param body: Created user object
     :type body: dict | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = User.from_dict(connexion.request.get_json())
+        body = User.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
 
 
-def create_users_with_array_input(body):
-    """
-    Creates list of users with given input array
-    
+def create_users_with_array_input(body):  # noqa: E501
+    """Creates list of users with given input array
+
+     # noqa: E501
+
     :param body: List of user object
     :type body: list | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = [User.from_dict(d) for d in connexion.request.get_json()]
+        body = [User.from_dict(d) for d in connexion.request.get_json()]  # noqa: E501
     return 'do some magic!'
 
 
-def create_users_with_list_input(body):
-    """
-    Creates list of users with given input array
-    
+def create_users_with_list_input(body):  # noqa: E501
+    """Creates list of users with given input array
+
+     # noqa: E501
+
     :param body: List of user object
     :type body: list | bytes
 
     :rtype: None
     """
     if connexion.request.is_json:
-        body = [User.from_dict(d) for d in connexion.request.get_json()]
+        body = [User.from_dict(d) for d in connexion.request.get_json()]  # noqa: E501
     return 'do some magic!'
 
 
-def delete_user(username):
-    """
-    Delete user
-    This can only be done by the logged in user.
+def delete_user(username):  # noqa: E501
+    """Delete user
+
+    This can only be done by the logged in user. # noqa: E501
+
     :param username: The name that needs to be deleted
     :type username: str
 
@@ -60,10 +63,11 @@ def delete_user(username):
     return 'do some magic!'
 
 
-def get_user_by_name(username):
-    """
-    Get user by user name
-    
+def get_user_by_name(username):  # noqa: E501
+    """Get user by user name
+
+     # noqa: E501
+
     :param username: The name that needs to be fetched. Use user1 for testing. 
     :type username: str
 
@@ -72,10 +76,11 @@ def get_user_by_name(username):
     return 'do some magic!'
 
 
-def login_user(username, password):
-    """
-    Logs user into the system
-    
+def login_user(username, password):  # noqa: E501
+    """Logs user into the system
+
+     # noqa: E501
+
     :param username: The user name for login
     :type username: str
     :param password: The password for login in clear text
@@ -86,20 +91,22 @@ def login_user(username, password):
     return 'do some magic!'
 
 
-def logout_user():
-    """
-    Logs out current logged in user session
-    
+def logout_user():  # noqa: E501
+    """Logs out current logged in user session
+
+     # noqa: E501
+
 
     :rtype: None
     """
     return 'do some magic!'
 
 
-def update_user(username, body):
-    """
-    Updated user
-    This can only be done by the logged in user.
+def update_user(username, body):  # noqa: E501
+    """Updated user
+
+    This can only be done by the logged in user. # noqa: E501
+
     :param username: name that need to be deleted
     :type username: str
     :param body: Updated user object
@@ -108,5 +115,5 @@ def update_user(username, body):
     :rtype: None
     """
     if connexion.request.is_json:
-        body = User.from_dict(connexion.request.get_json())
+        body = User.from_dict(connexion.request.get_json())  # noqa: E501
     return 'do some magic!'
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/encoder.py b/samples/server/petstore/flaskConnexion/swagger_server/encoder.py
index 3ff8cad5d72..61ba4721961 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/encoder.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/encoder.py
@@ -1,6 +1,8 @@
-from six import iteritems
-from swagger_server.models.base_model_ import Model
 from connexion.apps.flask_app import FlaskJSONEncoder
+import six
+
+from swagger_server.models.base_model_ import Model
+
 
 class JSONEncoder(FlaskJSONEncoder):
     include_nulls = False
@@ -8,11 +10,11 @@ class JSONEncoder(FlaskJSONEncoder):
     def default(self, o):
         if isinstance(o, Model):
             dikt = {}
-            for attr, _ in iteritems(o.swagger_types):
+            for attr, _ in six.iteritems(o.swagger_types):
                 value = getattr(o, attr)
                 if value is None and not self.include_nulls:
                     continue
                 attr = o.attribute_map[attr]
                 dikt[attr] = value
             return dikt
-        return FlaskJSONEncoder.default(self, o)
\ No newline at end of file
+        return FlaskJSONEncoder.default(self, o)
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/__init__.py b/samples/server/petstore/flaskConnexion/swagger_server/models/__init__.py
index 6571ad28e0f..fcf8253348d 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/__init__.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/__init__.py
@@ -1,10 +1,11 @@
 # coding: utf-8
 
+# flake8: noqa
 from __future__ import absolute_import
 # import models into model package
-from .api_response import ApiResponse
-from .category import Category
-from .order import Order
-from .pet import Pet
-from .tag import Tag
-from .user import User
+from swagger_server.models.api_response import ApiResponse
+from swagger_server.models.category import Category
+from swagger_server.models.order import Order
+from swagger_server.models.pet import Pet
+from swagger_server.models.tag import Tag
+from swagger_server.models.user import User
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/api_response.py b/samples/server/petstore/flaskConnexion/swagger_server/models/api_response.py
index 8b7cecc3398..17e3d36ce61 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/api_response.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/api_response.py
@@ -1,28 +1,28 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class ApiResponse(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, code: int=None, type: str=None, message: str=None):  # noqa: E501
+        """ApiResponse - a model defined in Swagger
 
-    def __init__(self, code: int=None, type: str=None, message: str=None):
-        """
-        ApiResponse - a model defined in Swagger
-
-        :param code: The code of this ApiResponse.
+        :param code: The code of this ApiResponse.  # noqa: E501
         :type code: int
-        :param type: The type of this ApiResponse.
+        :param type: The type of this ApiResponse.  # noqa: E501
         :type type: str
-        :param message: The message of this ApiResponse.
+        :param message: The message of this ApiResponse.  # noqa: E501
         :type message: str
         """
         self.swagger_types = {
@@ -43,20 +43,19 @@ class ApiResponse(Model):
 
     @classmethod
     def from_dict(cls, dikt) -> 'ApiResponse':
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The ApiResponse of this ApiResponse.
+        :return: The ApiResponse of this ApiResponse.  # noqa: E501
         :rtype: ApiResponse
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def code(self) -> int:
-        """
-        Gets the code of this ApiResponse.
+        """Gets the code of this ApiResponse.
+
 
         :return: The code of this ApiResponse.
         :rtype: int
@@ -65,8 +64,8 @@ class ApiResponse(Model):
 
     @code.setter
     def code(self, code: int):
-        """
-        Sets the code of this ApiResponse.
+        """Sets the code of this ApiResponse.
+
 
         :param code: The code of this ApiResponse.
         :type code: int
@@ -76,8 +75,8 @@ class ApiResponse(Model):
 
     @property
     def type(self) -> str:
-        """
-        Gets the type of this ApiResponse.
+        """Gets the type of this ApiResponse.
+
 
         :return: The type of this ApiResponse.
         :rtype: str
@@ -86,8 +85,8 @@ class ApiResponse(Model):
 
     @type.setter
     def type(self, type: str):
-        """
-        Sets the type of this ApiResponse.
+        """Sets the type of this ApiResponse.
+
 
         :param type: The type of this ApiResponse.
         :type type: str
@@ -97,8 +96,8 @@ class ApiResponse(Model):
 
     @property
     def message(self) -> str:
-        """
-        Gets the message of this ApiResponse.
+        """Gets the message of this ApiResponse.
+
 
         :return: The message of this ApiResponse.
         :rtype: str
@@ -107,12 +106,11 @@ class ApiResponse(Model):
 
     @message.setter
     def message(self, message: str):
-        """
-        Sets the message of this ApiResponse.
+        """Sets the message of this ApiResponse.
+
 
         :param message: The message of this ApiResponse.
         :type message: str
         """
 
         self._message = message
-
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/base_model_.py b/samples/server/petstore/flaskConnexion/swagger_server/models/base_model_.py
index 5202b30fb63..97999c3d323 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/base_model_.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/base_model_.py
@@ -1,34 +1,35 @@
-from pprint import pformat
-from typing import TypeVar, Type
-from six import iteritems
-from ..util import deserialize_model
+import pprint
 
-T = TypeVar('T')
+import six
+import typing
+
+from swagger_server import util
+
+T = typing.TypeVar('T')
 
 
 class Model(object):
-    # swaggerTypes: The key is attribute name and the value is attribute type.
+    # swaggerTypes: The key is attribute name and the
+    # value is attribute type.
     swagger_types = {}
 
-    # attributeMap: The key is attribute name and the value is json key in definition.
+    # attributeMap: The key is attribute name and the
+    # value is json key in definition.
     attribute_map = {}
 
     @classmethod
-    def from_dict(cls: Type[T], dikt) -> T:
-        """
-        Returns the dict as a model
-        """
-        return deserialize_model(dikt, cls)
+    def from_dict(cls: typing.Type[T], dikt) -> T:
+        """Returns the dict as a model"""
+        return util.deserialize_model(dikt, cls)
 
     def to_dict(self):
-        """
-        Returns the model properties as a dict
+        """Returns the model properties as a dict
 
         :rtype: dict
         """
         result = {}
 
-        for attr, _ in iteritems(self.swagger_types):
+        for attr, _ in six.iteritems(self.swagger_types):
             value = getattr(self, attr)
             if isinstance(value, list):
                 result[attr] = list(map(
@@ -49,27 +50,20 @@ class Model(object):
         return result
 
     def to_str(self):
-        """
-        Returns the string representation of the model
+        """Returns the string representation of the model
 
         :rtype: str
         """
-        return pformat(self.to_dict())
+        return pprint.pformat(self.to_dict())
 
     def __repr__(self):
-        """
-        For `print` and `pprint`
-        """
+        """For `print` and `pprint`"""
         return self.to_str()
 
     def __eq__(self, other):
-        """
-        Returns true if both objects are equal
-        """
+        """Returns true if both objects are equal"""
         return self.__dict__ == other.__dict__
 
     def __ne__(self, other):
-        """
-        Returns true if both objects are not equal
-        """
-        return not self == other
\ No newline at end of file
+        """Returns true if both objects are not equal"""
+        return not self == other
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/category.py b/samples/server/petstore/flaskConnexion/swagger_server/models/category.py
index 42657e8447d..5a5bab5913d 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/category.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/category.py
@@ -1,26 +1,26 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class Category(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id: int=None, name: str=None):  # noqa: E501
+        """Category - a model defined in Swagger
 
-    def __init__(self, id: int=None, name: str=None):
-        """
-        Category - a model defined in Swagger
-
-        :param id: The id of this Category.
+        :param id: The id of this Category.  # noqa: E501
         :type id: int
-        :param name: The name of this Category.
+        :param name: The name of this Category.  # noqa: E501
         :type name: str
         """
         self.swagger_types = {
@@ -38,20 +38,19 @@ class Category(Model):
 
     @classmethod
     def from_dict(cls, dikt) -> 'Category':
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Category of this Category.
+        :return: The Category of this Category.  # noqa: E501
         :rtype: Category
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self) -> int:
-        """
-        Gets the id of this Category.
+        """Gets the id of this Category.
+
 
         :return: The id of this Category.
         :rtype: int
@@ -60,8 +59,8 @@ class Category(Model):
 
     @id.setter
     def id(self, id: int):
-        """
-        Sets the id of this Category.
+        """Sets the id of this Category.
+
 
         :param id: The id of this Category.
         :type id: int
@@ -71,8 +70,8 @@ class Category(Model):
 
     @property
     def name(self) -> str:
-        """
-        Gets the name of this Category.
+        """Gets the name of this Category.
+
 
         :return: The name of this Category.
         :rtype: str
@@ -81,12 +80,11 @@ class Category(Model):
 
     @name.setter
     def name(self, name: str):
-        """
-        Sets the name of this Category.
+        """Sets the name of this Category.
+
 
         :param name: The name of this Category.
         :type name: str
         """
 
         self._name = name
-
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/order.py b/samples/server/petstore/flaskConnexion/swagger_server/models/order.py
index deffb5236b2..5b36925d07f 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/order.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/order.py
@@ -1,34 +1,34 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class Order(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id: int=None, pet_id: int=None, quantity: int=None, ship_date: datetime=None, status: str=None, complete: bool=False):  # noqa: E501
+        """Order - a model defined in Swagger
 
-    def __init__(self, id: int=None, pet_id: int=None, quantity: int=None, ship_date: datetime=None, status: str=None, complete: bool=False):
-        """
-        Order - a model defined in Swagger
-
-        :param id: The id of this Order.
+        :param id: The id of this Order.  # noqa: E501
         :type id: int
-        :param pet_id: The pet_id of this Order.
+        :param pet_id: The pet_id of this Order.  # noqa: E501
         :type pet_id: int
-        :param quantity: The quantity of this Order.
+        :param quantity: The quantity of this Order.  # noqa: E501
         :type quantity: int
-        :param ship_date: The ship_date of this Order.
+        :param ship_date: The ship_date of this Order.  # noqa: E501
         :type ship_date: datetime
-        :param status: The status of this Order.
+        :param status: The status of this Order.  # noqa: E501
         :type status: str
-        :param complete: The complete of this Order.
+        :param complete: The complete of this Order.  # noqa: E501
         :type complete: bool
         """
         self.swagger_types = {
@@ -58,20 +58,19 @@ class Order(Model):
 
     @classmethod
     def from_dict(cls, dikt) -> 'Order':
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Order of this Order.
+        :return: The Order of this Order.  # noqa: E501
         :rtype: Order
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self) -> int:
-        """
-        Gets the id of this Order.
+        """Gets the id of this Order.
+
 
         :return: The id of this Order.
         :rtype: int
@@ -80,8 +79,8 @@ class Order(Model):
 
     @id.setter
     def id(self, id: int):
-        """
-        Sets the id of this Order.
+        """Sets the id of this Order.
+
 
         :param id: The id of this Order.
         :type id: int
@@ -91,8 +90,8 @@ class Order(Model):
 
     @property
     def pet_id(self) -> int:
-        """
-        Gets the pet_id of this Order.
+        """Gets the pet_id of this Order.
+
 
         :return: The pet_id of this Order.
         :rtype: int
@@ -101,8 +100,8 @@ class Order(Model):
 
     @pet_id.setter
     def pet_id(self, pet_id: int):
-        """
-        Sets the pet_id of this Order.
+        """Sets the pet_id of this Order.
+
 
         :param pet_id: The pet_id of this Order.
         :type pet_id: int
@@ -112,8 +111,8 @@ class Order(Model):
 
     @property
     def quantity(self) -> int:
-        """
-        Gets the quantity of this Order.
+        """Gets the quantity of this Order.
+
 
         :return: The quantity of this Order.
         :rtype: int
@@ -122,8 +121,8 @@ class Order(Model):
 
     @quantity.setter
     def quantity(self, quantity: int):
-        """
-        Sets the quantity of this Order.
+        """Sets the quantity of this Order.
+
 
         :param quantity: The quantity of this Order.
         :type quantity: int
@@ -133,8 +132,8 @@ class Order(Model):
 
     @property
     def ship_date(self) -> datetime:
-        """
-        Gets the ship_date of this Order.
+        """Gets the ship_date of this Order.
+
 
         :return: The ship_date of this Order.
         :rtype: datetime
@@ -143,8 +142,8 @@ class Order(Model):
 
     @ship_date.setter
     def ship_date(self, ship_date: datetime):
-        """
-        Sets the ship_date of this Order.
+        """Sets the ship_date of this Order.
+
 
         :param ship_date: The ship_date of this Order.
         :type ship_date: datetime
@@ -154,9 +153,9 @@ class Order(Model):
 
     @property
     def status(self) -> str:
-        """
-        Gets the status of this Order.
-        Order Status
+        """Gets the status of this Order.
+
+        Order Status  # noqa: E501
 
         :return: The status of this Order.
         :rtype: str
@@ -165,14 +164,14 @@ class Order(Model):
 
     @status.setter
     def status(self, status: str):
-        """
-        Sets the status of this Order.
-        Order Status
+        """Sets the status of this Order.
+
+        Order Status  # noqa: E501
 
         :param status: The status of this Order.
         :type status: str
         """
-        allowed_values = ["placed", "approved", "delivered"]
+        allowed_values = ["placed", "approved", "delivered"]  # noqa: E501
         if status not in allowed_values:
             raise ValueError(
                 "Invalid value for `status` ({0}), must be one of {1}"
@@ -183,8 +182,8 @@ class Order(Model):
 
     @property
     def complete(self) -> bool:
-        """
-        Gets the complete of this Order.
+        """Gets the complete of this Order.
+
 
         :return: The complete of this Order.
         :rtype: bool
@@ -193,12 +192,11 @@ class Order(Model):
 
     @complete.setter
     def complete(self, complete: bool):
-        """
-        Sets the complete of this Order.
+        """Sets the complete of this Order.
+
 
         :param complete: The complete of this Order.
         :type complete: bool
         """
 
         self._complete = complete
-
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/pet.py b/samples/server/petstore/flaskConnexion/swagger_server/models/pet.py
index 30173e024fb..8c511d9801a 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/pet.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/pet.py
@@ -1,36 +1,36 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from swagger_server.models.category import Category
-from swagger_server.models.tag import Tag
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server.models.category import Category  # noqa: E501
+from swagger_server.models.tag import Tag  # noqa: E501
+from swagger_server import util
 
 
 class Pet(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id: int=None, category: Category=None, name: str=None, photo_urls: List[str]=None, tags: List[Tag]=None, status: str=None):  # noqa: E501
+        """Pet - a model defined in Swagger
 
-    def __init__(self, id: int=None, category: Category=None, name: str=None, photo_urls: List[str]=None, tags: List[Tag]=None, status: str=None):
-        """
-        Pet - a model defined in Swagger
-
-        :param id: The id of this Pet.
+        :param id: The id of this Pet.  # noqa: E501
         :type id: int
-        :param category: The category of this Pet.
+        :param category: The category of this Pet.  # noqa: E501
         :type category: Category
-        :param name: The name of this Pet.
+        :param name: The name of this Pet.  # noqa: E501
         :type name: str
-        :param photo_urls: The photo_urls of this Pet.
+        :param photo_urls: The photo_urls of this Pet.  # noqa: E501
         :type photo_urls: List[str]
-        :param tags: The tags of this Pet.
+        :param tags: The tags of this Pet.  # noqa: E501
         :type tags: List[Tag]
-        :param status: The status of this Pet.
+        :param status: The status of this Pet.  # noqa: E501
         :type status: str
         """
         self.swagger_types = {
@@ -60,20 +60,19 @@ class Pet(Model):
 
     @classmethod
     def from_dict(cls, dikt) -> 'Pet':
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Pet of this Pet.
+        :return: The Pet of this Pet.  # noqa: E501
         :rtype: Pet
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self) -> int:
-        """
-        Gets the id of this Pet.
+        """Gets the id of this Pet.
+
 
         :return: The id of this Pet.
         :rtype: int
@@ -82,8 +81,8 @@ class Pet(Model):
 
     @id.setter
     def id(self, id: int):
-        """
-        Sets the id of this Pet.
+        """Sets the id of this Pet.
+
 
         :param id: The id of this Pet.
         :type id: int
@@ -93,8 +92,8 @@ class Pet(Model):
 
     @property
     def category(self) -> Category:
-        """
-        Gets the category of this Pet.
+        """Gets the category of this Pet.
+
 
         :return: The category of this Pet.
         :rtype: Category
@@ -103,8 +102,8 @@ class Pet(Model):
 
     @category.setter
     def category(self, category: Category):
-        """
-        Sets the category of this Pet.
+        """Sets the category of this Pet.
+
 
         :param category: The category of this Pet.
         :type category: Category
@@ -114,8 +113,8 @@ class Pet(Model):
 
     @property
     def name(self) -> str:
-        """
-        Gets the name of this Pet.
+        """Gets the name of this Pet.
+
 
         :return: The name of this Pet.
         :rtype: str
@@ -124,21 +123,21 @@ class Pet(Model):
 
     @name.setter
     def name(self, name: str):
-        """
-        Sets the name of this Pet.
+        """Sets the name of this Pet.
+
 
         :param name: The name of this Pet.
         :type name: str
         """
         if name is None:
-            raise ValueError("Invalid value for `name`, must not be `None`")
+            raise ValueError("Invalid value for `name`, must not be `None`")  # noqa: E501
 
         self._name = name
 
     @property
     def photo_urls(self) -> List[str]:
-        """
-        Gets the photo_urls of this Pet.
+        """Gets the photo_urls of this Pet.
+
 
         :return: The photo_urls of this Pet.
         :rtype: List[str]
@@ -147,21 +146,21 @@ class Pet(Model):
 
     @photo_urls.setter
     def photo_urls(self, photo_urls: List[str]):
-        """
-        Sets the photo_urls of this Pet.
+        """Sets the photo_urls of this Pet.
+
 
         :param photo_urls: The photo_urls of this Pet.
         :type photo_urls: List[str]
         """
         if photo_urls is None:
-            raise ValueError("Invalid value for `photo_urls`, must not be `None`")
+            raise ValueError("Invalid value for `photo_urls`, must not be `None`")  # noqa: E501
 
         self._photo_urls = photo_urls
 
     @property
     def tags(self) -> List[Tag]:
-        """
-        Gets the tags of this Pet.
+        """Gets the tags of this Pet.
+
 
         :return: The tags of this Pet.
         :rtype: List[Tag]
@@ -170,8 +169,8 @@ class Pet(Model):
 
     @tags.setter
     def tags(self, tags: List[Tag]):
-        """
-        Sets the tags of this Pet.
+        """Sets the tags of this Pet.
+
 
         :param tags: The tags of this Pet.
         :type tags: List[Tag]
@@ -181,9 +180,9 @@ class Pet(Model):
 
     @property
     def status(self) -> str:
-        """
-        Gets the status of this Pet.
-        pet status in the store
+        """Gets the status of this Pet.
+
+        pet status in the store  # noqa: E501
 
         :return: The status of this Pet.
         :rtype: str
@@ -192,14 +191,14 @@ class Pet(Model):
 
     @status.setter
     def status(self, status: str):
-        """
-        Sets the status of this Pet.
-        pet status in the store
+        """Sets the status of this Pet.
+
+        pet status in the store  # noqa: E501
 
         :param status: The status of this Pet.
         :type status: str
         """
-        allowed_values = ["available", "pending", "sold"]
+        allowed_values = ["available", "pending", "sold"]  # noqa: E501
         if status not in allowed_values:
             raise ValueError(
                 "Invalid value for `status` ({0}), must be one of {1}"
@@ -207,4 +206,3 @@ class Pet(Model):
             )
 
         self._status = status
-
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/tag.py b/samples/server/petstore/flaskConnexion/swagger_server/models/tag.py
index 9931b7476b1..62ba5b21be8 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/tag.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/tag.py
@@ -1,26 +1,26 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class Tag(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id: int=None, name: str=None):  # noqa: E501
+        """Tag - a model defined in Swagger
 
-    def __init__(self, id: int=None, name: str=None):
-        """
-        Tag - a model defined in Swagger
-
-        :param id: The id of this Tag.
+        :param id: The id of this Tag.  # noqa: E501
         :type id: int
-        :param name: The name of this Tag.
+        :param name: The name of this Tag.  # noqa: E501
         :type name: str
         """
         self.swagger_types = {
@@ -38,20 +38,19 @@ class Tag(Model):
 
     @classmethod
     def from_dict(cls, dikt) -> 'Tag':
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The Tag of this Tag.
+        :return: The Tag of this Tag.  # noqa: E501
         :rtype: Tag
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self) -> int:
-        """
-        Gets the id of this Tag.
+        """Gets the id of this Tag.
+
 
         :return: The id of this Tag.
         :rtype: int
@@ -60,8 +59,8 @@ class Tag(Model):
 
     @id.setter
     def id(self, id: int):
-        """
-        Sets the id of this Tag.
+        """Sets the id of this Tag.
+
 
         :param id: The id of this Tag.
         :type id: int
@@ -71,8 +70,8 @@ class Tag(Model):
 
     @property
     def name(self) -> str:
-        """
-        Gets the name of this Tag.
+        """Gets the name of this Tag.
+
 
         :return: The name of this Tag.
         :rtype: str
@@ -81,12 +80,11 @@ class Tag(Model):
 
     @name.setter
     def name(self, name: str):
-        """
-        Sets the name of this Tag.
+        """Sets the name of this Tag.
+
 
         :param name: The name of this Tag.
         :type name: str
         """
 
         self._name = name
-
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/models/user.py b/samples/server/petstore/flaskConnexion/swagger_server/models/user.py
index c4ea4d373bc..bf1fd963c70 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/models/user.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/models/user.py
@@ -1,38 +1,38 @@
 # coding: utf-8
 
 from __future__ import absolute_import
-from .base_model_ import Model
-from datetime import date, datetime
-from typing import List, Dict
-from ..util import deserialize_model
+from datetime import date, datetime  # noqa: F401
+
+from typing import List, Dict  # noqa: F401
+
+from swagger_server.models.base_model_ import Model
+from swagger_server import util
 
 
 class User(Model):
-    """
-    NOTE: This class is auto generated by the swagger code generator program.
+    """NOTE: This class is auto generated by the swagger code generator program.
+
     Do not edit the class manually.
     """
 
+    def __init__(self, id: int=None, username: str=None, first_name: str=None, last_name: str=None, email: str=None, password: str=None, phone: str=None, user_status: int=None):  # noqa: E501
+        """User - a model defined in Swagger
 
-    def __init__(self, id: int=None, username: str=None, first_name: str=None, last_name: str=None, email: str=None, password: str=None, phone: str=None, user_status: int=None):
-        """
-        User - a model defined in Swagger
-
-        :param id: The id of this User.
+        :param id: The id of this User.  # noqa: E501
         :type id: int
-        :param username: The username of this User.
+        :param username: The username of this User.  # noqa: E501
         :type username: str
-        :param first_name: The first_name of this User.
+        :param first_name: The first_name of this User.  # noqa: E501
         :type first_name: str
-        :param last_name: The last_name of this User.
+        :param last_name: The last_name of this User.  # noqa: E501
         :type last_name: str
-        :param email: The email of this User.
+        :param email: The email of this User.  # noqa: E501
         :type email: str
-        :param password: The password of this User.
+        :param password: The password of this User.  # noqa: E501
         :type password: str
-        :param phone: The phone of this User.
+        :param phone: The phone of this User.  # noqa: E501
         :type phone: str
-        :param user_status: The user_status of this User.
+        :param user_status: The user_status of this User.  # noqa: E501
         :type user_status: int
         """
         self.swagger_types = {
@@ -68,20 +68,19 @@ class User(Model):
 
     @classmethod
     def from_dict(cls, dikt) -> 'User':
-        """
-        Returns the dict as a model
+        """Returns the dict as a model
 
         :param dikt: A dict.
         :type: dict
-        :return: The User of this User.
+        :return: The User of this User.  # noqa: E501
         :rtype: User
         """
-        return deserialize_model(dikt, cls)
+        return util.deserialize_model(dikt, cls)
 
     @property
     def id(self) -> int:
-        """
-        Gets the id of this User.
+        """Gets the id of this User.
+
 
         :return: The id of this User.
         :rtype: int
@@ -90,8 +89,8 @@ class User(Model):
 
     @id.setter
     def id(self, id: int):
-        """
-        Sets the id of this User.
+        """Sets the id of this User.
+
 
         :param id: The id of this User.
         :type id: int
@@ -101,8 +100,8 @@ class User(Model):
 
     @property
     def username(self) -> str:
-        """
-        Gets the username of this User.
+        """Gets the username of this User.
+
 
         :return: The username of this User.
         :rtype: str
@@ -111,8 +110,8 @@ class User(Model):
 
     @username.setter
     def username(self, username: str):
-        """
-        Sets the username of this User.
+        """Sets the username of this User.
+
 
         :param username: The username of this User.
         :type username: str
@@ -122,8 +121,8 @@ class User(Model):
 
     @property
     def first_name(self) -> str:
-        """
-        Gets the first_name of this User.
+        """Gets the first_name of this User.
+
 
         :return: The first_name of this User.
         :rtype: str
@@ -132,8 +131,8 @@ class User(Model):
 
     @first_name.setter
     def first_name(self, first_name: str):
-        """
-        Sets the first_name of this User.
+        """Sets the first_name of this User.
+
 
         :param first_name: The first_name of this User.
         :type first_name: str
@@ -143,8 +142,8 @@ class User(Model):
 
     @property
     def last_name(self) -> str:
-        """
-        Gets the last_name of this User.
+        """Gets the last_name of this User.
+
 
         :return: The last_name of this User.
         :rtype: str
@@ -153,8 +152,8 @@ class User(Model):
 
     @last_name.setter
     def last_name(self, last_name: str):
-        """
-        Sets the last_name of this User.
+        """Sets the last_name of this User.
+
 
         :param last_name: The last_name of this User.
         :type last_name: str
@@ -164,8 +163,8 @@ class User(Model):
 
     @property
     def email(self) -> str:
-        """
-        Gets the email of this User.
+        """Gets the email of this User.
+
 
         :return: The email of this User.
         :rtype: str
@@ -174,8 +173,8 @@ class User(Model):
 
     @email.setter
     def email(self, email: str):
-        """
-        Sets the email of this User.
+        """Sets the email of this User.
+
 
         :param email: The email of this User.
         :type email: str
@@ -185,8 +184,8 @@ class User(Model):
 
     @property
     def password(self) -> str:
-        """
-        Gets the password of this User.
+        """Gets the password of this User.
+
 
         :return: The password of this User.
         :rtype: str
@@ -195,8 +194,8 @@ class User(Model):
 
     @password.setter
     def password(self, password: str):
-        """
-        Sets the password of this User.
+        """Sets the password of this User.
+
 
         :param password: The password of this User.
         :type password: str
@@ -206,8 +205,8 @@ class User(Model):
 
     @property
     def phone(self) -> str:
-        """
-        Gets the phone of this User.
+        """Gets the phone of this User.
+
 
         :return: The phone of this User.
         :rtype: str
@@ -216,8 +215,8 @@ class User(Model):
 
     @phone.setter
     def phone(self, phone: str):
-        """
-        Sets the phone of this User.
+        """Sets the phone of this User.
+
 
         :param phone: The phone of this User.
         :type phone: str
@@ -227,9 +226,9 @@ class User(Model):
 
     @property
     def user_status(self) -> int:
-        """
-        Gets the user_status of this User.
-        User Status
+        """Gets the user_status of this User.
+
+        User Status  # noqa: E501
 
         :return: The user_status of this User.
         :rtype: int
@@ -238,13 +237,12 @@ class User(Model):
 
     @user_status.setter
     def user_status(self, user_status: int):
-        """
-        Sets the user_status of this User.
-        User Status
+        """Sets the user_status of this User.
+
+        User Status  # noqa: E501
 
         :param user_status: The user_status of this User.
         :type user_status: int
         """
 
         self._user_status = user_status
-
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/test/__init__.py b/samples/server/petstore/flaskConnexion/swagger_server/test/__init__.py
index 77b10c3a012..644506301ce 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/test/__init__.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/test/__init__.py
@@ -1,8 +1,10 @@
-from flask_testing import TestCase
-from ..encoder import JSONEncoder
-import connexion
 import logging
 
+import connexion
+from flask_testing import TestCase
+
+from swagger_server.encoder import JSONEncoder
+
 
 class BaseTestCase(TestCase):
 
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/test/test_pet_controller.py b/samples/server/petstore/flaskConnexion/swagger_server/test/test_pet_controller.py
index b99269a991a..fb4c34ea3e1 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/test/test_pet_controller.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/test/test_pet_controller.py
@@ -2,115 +2,124 @@
 
 from __future__ import absolute_import
 
-from swagger_server.models.api_response import ApiResponse
-from swagger_server.models.pet import Pet
-from . import BaseTestCase
-from six import BytesIO
 from flask import json
+from six import BytesIO
+
+from swagger_server.models.api_response import ApiResponse  # noqa: E501
+from swagger_server.models.pet import Pet  # noqa: E501
+from swagger_server.test import BaseTestCase
 
 
 class TestPetController(BaseTestCase):
-    """ PetController integration test stubs """
+    """PetController integration test stubs"""
 
     def test_add_pet(self):
-        """
-        Test case for add_pet
+        """Test case for add_pet
 
         Add a new pet to the store
         """
         body = Pet()
-        response = self.client.open('/v2/pet',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_delete_pet(self):
-        """
-        Test case for delete_pet
+        """Test case for delete_pet
 
         Deletes a pet
         """
         headers = [('api_key', 'api_key_example')]
-        response = self.client.open('/v2/pet/{petId}'.format(petId=789),
-                                    method='DELETE',
-                                    headers=headers)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}'.format(petId=789),
+            method='DELETE',
+            headers=headers)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_find_pets_by_status(self):
-        """
-        Test case for find_pets_by_status
+        """Test case for find_pets_by_status
 
         Finds Pets by status
         """
         query_string = [('status', 'available')]
-        response = self.client.open('/v2/pet/findByStatus',
-                                    method='GET',
-                                    query_string=query_string)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/findByStatus',
+            method='GET',
+            query_string=query_string)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_find_pets_by_tags(self):
-        """
-        Test case for find_pets_by_tags
+        """Test case for find_pets_by_tags
 
         Finds Pets by tags
         """
         query_string = [('tags', 'tags_example')]
-        response = self.client.open('/v2/pet/findByTags',
-                                    method='GET',
-                                    query_string=query_string)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/findByTags',
+            method='GET',
+            query_string=query_string)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_pet_by_id(self):
-        """
-        Test case for get_pet_by_id
+        """Test case for get_pet_by_id
 
         Find pet by ID
         """
-        response = self.client.open('/v2/pet/{petId}'.format(petId=789),
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}'.format(petId=789),
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_update_pet(self):
-        """
-        Test case for update_pet
+        """Test case for update_pet
 
         Update an existing pet
         """
         body = Pet()
-        response = self.client.open('/v2/pet',
-                                    method='PUT',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet',
+            method='PUT',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_update_pet_with_form(self):
-        """
-        Test case for update_pet_with_form
+        """Test case for update_pet_with_form
 
         Updates a pet in the store with form data
         """
         data = dict(name='name_example',
                     status='status_example')
-        response = self.client.open('/v2/pet/{petId}'.format(petId=789),
-                                    method='POST',
-                                    data=data,
-                                    content_type='application/x-www-form-urlencoded')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}'.format(petId=789),
+            method='POST',
+            data=data,
+            content_type='application/x-www-form-urlencoded')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_upload_file(self):
-        """
-        Test case for upload_file
+        """Test case for upload_file
 
         uploads an image
         """
         data = dict(additionalMetadata='additionalMetadata_example',
                     file=(BytesIO(b'some file data'), 'file.txt'))
-        response = self.client.open('/v2/pet/{petId}/uploadImage'.format(petId=789),
-                                    method='POST',
-                                    data=data,
-                                    content_type='multipart/form-data')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/pet/{petId}/uploadImage'.format(petId=789),
+            method='POST',
+            data=data,
+            content_type='multipart/form-data')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
 
 if __name__ == '__main__':
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/test/test_store_controller.py b/samples/server/petstore/flaskConnexion/swagger_server/test/test_store_controller.py
index 0a5360b4e25..854e18600fc 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/test/test_store_controller.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/test/test_store_controller.py
@@ -2,57 +2,62 @@
 
 from __future__ import absolute_import
 
-from swagger_server.models.order import Order
-from . import BaseTestCase
-from six import BytesIO
 from flask import json
+from six import BytesIO
+
+from swagger_server.models.order import Order  # noqa: E501
+from swagger_server.test import BaseTestCase
 
 
 class TestStoreController(BaseTestCase):
-    """ StoreController integration test stubs """
+    """StoreController integration test stubs"""
 
     def test_delete_order(self):
-        """
-        Test case for delete_order
+        """Test case for delete_order
 
         Delete purchase order by ID
         """
-        response = self.client.open('/v2/store/order/{orderId}'.format(orderId='orderId_example'),
-                                    method='DELETE')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/order/{orderId}'.format(orderId='orderId_example'),
+            method='DELETE')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_inventory(self):
-        """
-        Test case for get_inventory
+        """Test case for get_inventory
 
         Returns pet inventories by status
         """
-        response = self.client.open('/v2/store/inventory',
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/inventory',
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_order_by_id(self):
-        """
-        Test case for get_order_by_id
+        """Test case for get_order_by_id
 
         Find purchase order by ID
         """
-        response = self.client.open('/v2/store/order/{orderId}'.format(orderId=5),
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/order/{orderId}'.format(orderId=5),
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_place_order(self):
-        """
-        Test case for place_order
+        """Test case for place_order
 
         Place an order for a pet
         """
         body = Order()
-        response = self.client.open('/v2/store/order',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/store/order',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
 
 if __name__ == '__main__':
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/test/test_user_controller.py b/samples/server/petstore/flaskConnexion/swagger_server/test/test_user_controller.py
index 867de3c0150..30e1885afab 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/test/test_user_controller.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/test/test_user_controller.py
@@ -2,109 +2,118 @@
 
 from __future__ import absolute_import
 
-from swagger_server.models.user import User
-from . import BaseTestCase
-from six import BytesIO
 from flask import json
+from six import BytesIO
+
+from swagger_server.models.user import User  # noqa: E501
+from swagger_server.test import BaseTestCase
 
 
 class TestUserController(BaseTestCase):
-    """ UserController integration test stubs """
+    """UserController integration test stubs"""
 
     def test_create_user(self):
-        """
-        Test case for create_user
+        """Test case for create_user
 
         Create user
         """
         body = User()
-        response = self.client.open('/v2/user',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_create_users_with_array_input(self):
-        """
-        Test case for create_users_with_array_input
+        """Test case for create_users_with_array_input
 
         Creates list of users with given input array
         """
         body = [User()]
-        response = self.client.open('/v2/user/createWithArray',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/createWithArray',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_create_users_with_list_input(self):
-        """
-        Test case for create_users_with_list_input
+        """Test case for create_users_with_list_input
 
         Creates list of users with given input array
         """
         body = [User()]
-        response = self.client.open('/v2/user/createWithList',
-                                    method='POST',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/createWithList',
+            method='POST',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_delete_user(self):
-        """
-        Test case for delete_user
+        """Test case for delete_user
 
         Delete user
         """
-        response = self.client.open('/v2/user/{username}'.format(username='username_example'),
-                                    method='DELETE')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/{username}'.format(username='username_example'),
+            method='DELETE')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_get_user_by_name(self):
-        """
-        Test case for get_user_by_name
+        """Test case for get_user_by_name
 
         Get user by user name
         """
-        response = self.client.open('/v2/user/{username}'.format(username='username_example'),
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/{username}'.format(username='username_example'),
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_login_user(self):
-        """
-        Test case for login_user
+        """Test case for login_user
 
         Logs user into the system
         """
         query_string = [('username', 'username_example'),
                         ('password', 'password_example')]
-        response = self.client.open('/v2/user/login',
-                                    method='GET',
-                                    query_string=query_string)
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/login',
+            method='GET',
+            query_string=query_string)
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_logout_user(self):
-        """
-        Test case for logout_user
+        """Test case for logout_user
 
         Logs out current logged in user session
         """
-        response = self.client.open('/v2/user/logout',
-                                    method='GET')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/logout',
+            method='GET')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
     def test_update_user(self):
-        """
-        Test case for update_user
+        """Test case for update_user
 
         Updated user
         """
         body = User()
-        response = self.client.open('/v2/user/{username}'.format(username='username_example'),
-                                    method='PUT',
-                                    data=json.dumps(body),
-                                    content_type='application/json')
-        self.assert200(response, "Response body is : " + response.data.decode('utf-8'))
+        response = self.client.open(
+            '/v2/user/{username}'.format(username='username_example'),
+            method='PUT',
+            data=json.dumps(body),
+            content_type='application/json')
+        self.assert200(response,
+                       'Response body is : ' + response.data.decode('utf-8'))
 
 
 if __name__ == '__main__':
diff --git a/samples/server/petstore/flaskConnexion/swagger_server/util.py b/samples/server/petstore/flaskConnexion/swagger_server/util.py
index 40c72d43ebd..b0576ef9594 100644
--- a/samples/server/petstore/flaskConnexion/swagger_server/util.py
+++ b/samples/server/petstore/flaskConnexion/swagger_server/util.py
@@ -1,11 +1,11 @@
-from typing import GenericMeta
-from datetime import datetime, date
-from six import integer_types, iteritems
+import datetime
+
+import six
+import typing
 
 
 def _deserialize(data, klass):
-    """
-    Deserializes dict, list, str into an object.
+    """Deserializes dict, list, str into an object.
 
     :param data: dict, list or str.
     :param klass: class literal, or string of class name.
@@ -15,15 +15,15 @@ def _deserialize(data, klass):
     if data is None:
         return None
 
-    if klass in integer_types or klass in (float, str, bool):
+    if klass in six.integer_types or klass in (float, str, bool):
         return _deserialize_primitive(data, klass)
     elif klass == object:
         return _deserialize_object(data)
-    elif klass == date:
+    elif klass == datetime.date:
         return deserialize_date(data)
-    elif klass == datetime:
+    elif klass == datetime.datetime:
         return deserialize_datetime(data)
-    elif type(klass) == GenericMeta:
+    elif type(klass) == typing.GenericMeta:
         if klass.__extra__ == list:
             return _deserialize_list(data, klass.__args__[0])
         if klass.__extra__ == dict:
@@ -33,8 +33,7 @@ def _deserialize(data, klass):
 
 
 def _deserialize_primitive(data, klass):
-    """
-    Deserializes to primitive type.
+    """Deserializes to primitive type.
 
     :param data: data to deserialize.
     :param klass: class literal.
@@ -52,8 +51,7 @@ def _deserialize_primitive(data, klass):
 
 
 def _deserialize_object(value):
-    """
-    Return a original value.
+    """Return a original value.
 
     :return: object.
     """
@@ -61,8 +59,7 @@ def _deserialize_object(value):
 
 
 def deserialize_date(string):
-    """
-    Deserializes string to date.
+    """Deserializes string to date.
 
     :param string: str.
     :type string: str
@@ -77,8 +74,7 @@ def deserialize_date(string):
 
 
 def deserialize_datetime(string):
-    """
-    Deserializes string to datetime.
+    """Deserializes string to datetime.
 
     The string should be in iso8601 datetime format.
 
@@ -95,8 +91,7 @@ def deserialize_datetime(string):
 
 
 def deserialize_model(data, klass):
-    """
-    Deserializes list or dict to model.
+    """Deserializes list or dict to model.
 
     :param data: dict, list.
     :type data: dict | list
@@ -108,7 +103,7 @@ def deserialize_model(data, klass):
     if not instance.swagger_types:
         return data
 
-    for attr, attr_type in iteritems(instance.swagger_types):
+    for attr, attr_type in six.iteritems(instance.swagger_types):
         if data is not None \
                 and instance.attribute_map[attr] in data \
                 and isinstance(data, (list, dict)):
@@ -119,8 +114,7 @@ def deserialize_model(data, klass):
 
 
 def _deserialize_list(data, boxed_type):
-    """
-    Deserializes a list and its elements.
+    """Deserializes a list and its elements.
 
     :param data: list to deserialize.
     :type data: list
@@ -133,10 +127,8 @@ def _deserialize_list(data, boxed_type):
             for sub_data in data]
 
 
-
 def _deserialize_dict(data, boxed_type):
-    """
-    Deserializes a dict and its elements.
+    """Deserializes a dict and its elements.
 
     :param data: dict to deserialize.
     :type data: dict
@@ -146,4 +138,4 @@ def _deserialize_dict(data, boxed_type):
     :rtype: dict
     """
     return {k: _deserialize(v, boxed_type)
-            for k, v in iteritems(data)}
+            for k, v in six.iteritems(data)}